diff --git a/.idea/libraries/avoscloud_sdk_v3_14_4.xml b/.idea/libraries/avoscloud_sdk_v3_14_4.xml
new file mode 100644
index 0000000..a5e8674
--- /dev/null
+++ b/.idea/libraries/avoscloud_sdk_v3_14_4.xml
@@ -0,0 +1,9 @@
+<component name="libraryTable">
+  <library name="avoscloud-sdk-v3.14.4">
+    <CLASSES>
+      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/cn.leancloud.android/avoscloud-sdk/v3.14.4/956ddd9b6d98ff5235326c2993f5caa796eee68c/avoscloud-sdk-v3.14.4.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>
\ No newline at end of file
diff --git a/.idea/libraries/fastjson_1_1_39_leancloud.xml b/.idea/libraries/fastjson_1_1_39_leancloud.xml
new file mode 100644
index 0000000..5e4788c
--- /dev/null
+++ b/.idea/libraries/fastjson_1_1_39_leancloud.xml
@@ -0,0 +1,11 @@
+<component name="libraryTable">
+  <library name="fastjson-1.1.39-leancloud">
+    <CLASSES>
+      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/cn.leancloud.android/fastjson/1.1.39-leancloud/94d4ebd4acdaf01d7445435382eea2d2d38e7534/fastjson-1.1.39-leancloud.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES>
+      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/cn.leancloud.android/fastjson/1.1.39-leancloud/ed3f6b73fc368aa19d76368cb2251e87f2dc21e8/fastjson-1.1.39-leancloud-sources.jar!/" />
+    </SOURCES>
+  </library>
+</component>
\ No newline at end of file
diff --git a/.idea/libraries/okhttp_2_6_0_leancloud.xml b/.idea/libraries/okhttp_2_6_0_leancloud.xml
new file mode 100644
index 0000000..eb98851
--- /dev/null
+++ b/.idea/libraries/okhttp_2_6_0_leancloud.xml
@@ -0,0 +1,11 @@
+<component name="libraryTable">
+  <library name="okhttp-2.6.0-leancloud">
+    <CLASSES>
+      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/cn.leancloud.android/okhttp/2.6.0-leancloud/7d1a8dbbc128e91cf41ab6eafaa741ab2a6ff930/okhttp-2.6.0-leancloud.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES>
+      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/cn.leancloud.android/okhttp/2.6.0-leancloud/af7e06d7da4db559b0be6d98493367f29baadddf/okhttp-2.6.0-leancloud-sources.jar!/" />
+    </SOURCES>
+  </library>
+</component>
\ No newline at end of file
diff --git a/.idea/libraries/okio_1_6_0_leancloud.xml b/.idea/libraries/okio_1_6_0_leancloud.xml
new file mode 100644
index 0000000..9d21fe0
--- /dev/null
+++ b/.idea/libraries/okio_1_6_0_leancloud.xml
@@ -0,0 +1,11 @@
+<component name="libraryTable">
+  <library name="okio-1.6.0-leancloud">
+    <CLASSES>
+      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/cn.leancloud.android/okio/1.6.0-leancloud/7086c00a30a6de0ee3b963ec2c3702d37f1de11d/okio-1.6.0-leancloud.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES>
+      <root url="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/cn.leancloud.android/okio/1.6.0-leancloud/8475fc6f2f813e53b310bcecebd6a4e332430dac/okio-1.6.0-leancloud-sources.jar!/" />
+    </SOURCES>
+  </library>
+</component>
\ No newline at end of file
diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index f0d68fd..35a5d31 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -26,30 +26,29 @@
   </component>
   <component name="ChangeListManager">
     <list default="true" id="b7cc4437-0591-4430-a184-ede1c9401155" name="Default" comment="">
-      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/SocialSDK_QQZone_3.xml" />
-      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/SocialSDK_WeiXin_2.xml" />
-      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/SocialSDK_email.xml" />
-      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/SocialSDK_sms.xml" />
-      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/SocialSDK_umengqq.xml" />
-      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/SocialSDK_umengsina.xml" />
-      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/SocialSDK_umengwx.xml" />
-      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/umeng_social_apiv6_0_0.xml" />
-      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/umeng_social_netv6_0_0.xml" />
-      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/umeng_social_viewv6_0_0.xml" />
-      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/App.java" />
-      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/wxapi/WXEntryActivity.java" />
+      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/avoscloud_sdk_v3_14_4.xml" />
+      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/fastjson_1_1_39_leancloud.xml" />
+      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/okhttp_2_6_0_leancloud.xml" />
+      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/.idea/libraries/okio_1_6_0_leancloud.xml" />
+      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/LoginActivity.java" />
+      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/app/src/main/res/layout/activity_login.xml" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/.idea/workspace.xml" afterPath="$PROJECT_DIR$/.idea/workspace.xml" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/app.iml" afterPath="$PROJECT_DIR$/app/app.iml" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/build.gradle" afterPath="$PROJECT_DIR$/app/build.gradle" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/src/main/AndroidManifest.xml" afterPath="$PROJECT_DIR$/app/src/main/AndroidManifest.xml" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/AcidActivity.java" afterPath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/AcidActivity.java" />
+      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/App.java" afterPath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/App.java" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/CardLayoutFragment.java" afterPath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/CardLayoutFragment.java" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/ExamActivity.java" afterPath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/ExamActivity.java" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MainActivity.java" afterPath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MainActivity.java" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MassActivity.java" afterPath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MassActivity.java" />
+      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/SettingsActivity.java" afterPath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/SettingsActivity.java" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/TitleActivity.java" afterPath="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/TitleActivity.java" />
+      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/src/main/res/values-en/strings.xml" afterPath="$PROJECT_DIR$/app/src/main/res/values-en/strings.xml" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/src/main/res/values-zh/strings.xml" afterPath="$PROJECT_DIR$/app/src/main/res/values-zh/strings.xml" />
-      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/gradle.properties" afterPath="$PROJECT_DIR$/gradle.properties" />
+      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/src/main/res/values/strings.xml" afterPath="$PROJECT_DIR$/app/src/main/res/values/strings.xml" />
+      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/app/src/main/res/xml/settings_general.xml" afterPath="$PROJECT_DIR$/app/src/main/res/xml/settings_general.xml" />
+      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/build.gradle" afterPath="$PROJECT_DIR$/build.gradle" />
     </list>
     <ignored path="Chemical-Tools-for-Android.iws" />
     <ignored path=".idea/workspace.xml" />
@@ -84,45 +83,45 @@
   </component>
   <component name="FileEditorManager">
     <leaf SIDE_TABS_SIZE_LIMIT_KEY="300">
-      <file leaf-file-name="build.gradle" pinned="false" current-in-tab="false">
-        <entry file="file://$PROJECT_DIR$/app/build.gradle">
-          <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="247">
-              <caret line="15" column="17" selection-start-line="15" selection-start-column="17" selection-end-line="15" selection-end-column="17" />
-              <folding />
-            </state>
-          </provider>
-        </entry>
-      </file>
-      <file leaf-file-name="MainActivity.java" pinned="false" current-in-tab="false">
-        <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MainActivity.java">
+      <file leaf-file-name="TitleActivity.java" pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/TitleActivity.java">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="323">
-              <caret line="208" column="56" selection-start-line="208" selection-start-column="56" selection-end-line="208" selection-end-column="56" />
+            <state relative-caret-position="399">
+              <caret line="95" column="57" selection-start-line="95" selection-start-column="57" selection-end-line="95" selection-end-column="57" />
               <folding>
                 <element signature="imports" expanded="true" />
+                <element signature="e#3508#6769#0" expanded="true" />
+                <element signature="e#6768#6769#0" expanded="true" />
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           </provider>
         </entry>
       </file>
-      <file leaf-file-name="array.xml" pinned="false" current-in-tab="false">
-        <entry file="file://$PROJECT_DIR$/app/src/main/res/values/array.xml">
+      <file leaf-file-name="ExamActivity.java" pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/ExamActivity.java">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="285">
-              <caret line="602" column="43" selection-start-line="602" selection-start-column="24" selection-end-line="602" selection-end-column="43" />
-              <folding />
+            <state relative-caret-position="39">
+              <caret line="52" column="53" selection-start-line="52" selection-start-column="53" selection-end-line="52" selection-end-column="53" />
+              <folding>
+                <element signature="e#1603#3185#0" expanded="true" />
+                <element signature="e#3184#3185#0" expanded="true" />
+                <element signature="e#7776#7831#0" expanded="true" />
+                <marker date="1475675569466" expanded="false" signature="15628:15656" ph="&quot;Chemical Tools&quot;" />
+                <marker date="1475675569466" expanded="true" signature="16376:16404" ph="&quot;Chemical Tools&quot;" />
+              </folding>
             </state>
           </provider>
         </entry>
       </file>
-      <file leaf-file-name="MassActivity.java" pinned="false" current-in-tab="true">
-        <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MassActivity.java">
+      <file leaf-file-name="MainActivity.java" pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MainActivity.java">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="152">
-              <caret line="291" column="46" selection-start-line="291" selection-start-column="46" selection-end-line="291" selection-end-column="46" />
+            <state relative-caret-position="226">
+              <caret line="122" column="50" selection-start-line="122" selection-start-column="50" selection-end-line="122" selection-end-column="50" />
               <folding>
-                <marker date="1475596387441" expanded="false" signature="13811:13839" ph="&quot;Chemical Tools&quot;" />
+                <element signature="imports" expanded="true" />
+                <element signature="e#6469#7610#0" expanded="true" />
+                <element signature="e#7609#7610#0" expanded="true" />
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@@ -131,87 +130,63 @@
       <file leaf-file-name="AcidActivity.java" pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/AcidActivity.java">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="19">
-              <caret line="325" column="59" selection-start-line="325" selection-start-column="59" selection-end-line="325" selection-end-column="59" />
+            <state relative-caret-position="240">
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               <folding>
                 <element signature="imports" expanded="true" />
-                <marker date="1475596408715" expanded="false" signature="15931:15959" ph="&quot;Chemical Tools&quot;" />
+                <element signature="e#9292#9861#0" expanded="true" />
+                <element signature="e#9860#9861#0" expanded="true" />
+                <marker date="1475675569451" expanded="false" signature="17138:17166" ph="&quot;Chemical Tools&quot;" />
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-      <file leaf-file-name="ExamActivity.java" pinned="false" current-in-tab="false">
-        <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/ExamActivity.java">
+      <file leaf-file-name="LoginActivity.java" pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/LoginActivity.java">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="285">
-              <caret line="275" column="64" selection-start-line="275" selection-start-column="64" selection-end-line="275" selection-end-column="64" />
+            <state relative-caret-position="418">
+              <caret line="351" column="51" selection-start-line="351" selection-start-column="51" selection-end-line="351" selection-end-column="51" />
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-                <marker date="1475596958376" expanded="true" signature="13883:13911" ph="&quot;Chemical Tools&quot;" />
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+                <element signature="e#15781#15782#0" expanded="true" />
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         </entry>
       </file>
-      <file leaf-file-name="AndroidManifest.xml" pinned="false" current-in-tab="false">
-        <entry file="file://$PROJECT_DIR$/app/src/main/AndroidManifest.xml">
+      <file leaf-file-name="SettingsActivity.java" pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/SettingsActivity.java">
           <provider selected="true" editor-type-id="text-editor">
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           </provider>
-          <provider editor-type-id="android-manifest">
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-      <file leaf-file-name="strings.xml" pinned="false" current-in-tab="false">
-        <entry file="file://$PROJECT_DIR$/app/src/main/res/values-zh/strings.xml">
+      <file leaf-file-name="build.gradle" pinned="false" current-in-tab="true">
+        <entry file="file://$PROJECT_DIR$/app/build.gradle">
           <provider selected="true" editor-type-id="text-editor">
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               <folding />
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-      <file leaf-file-name="TitleActivity.java" pinned="false" current-in-tab="false">
-        <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/TitleActivity.java">
+      <file leaf-file-name="MassActivity.java" pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MassActivity.java">
           <provider selected="true" editor-type-id="text-editor">
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+              <caret line="231" column="53" selection-start-line="231" selection-start-column="53" selection-end-line="231" selection-end-column="53" />
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-      <file leaf-file-name="CardLayoutFragment.java" pinned="false" current-in-tab="false">
-        <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/CardLayoutFragment.java">
-          <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="228">
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-              <folding>
-                <element signature="imports" expanded="true" />
+                <element signature="e#11621#12222#0" expanded="true" />
+                <element signature="e#12221#12222#0" expanded="true" />
+                <marker date="1475675569419" expanded="false" signature="15101:15129" ph="&quot;Chemical Tools&quot;" />
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@@ -1607,7 +1582,7 @@
     <option name="modificationStamps">
       <map>
         <entry key="$PROJECT_DIR$" value="4409885162417" />
-        <entry key="F:\GitHub\Chemical-Tools-for-Android" value="4411179383780" />
+        <entry key="F:\GitHub\Chemical-Tools-for-Android" value="4412467743294" />
       </map>
     </option>
     <option name="projectBuildClasspath">
@@ -1873,8 +1848,6 @@
   <component name="IdeDocumentHistory">
     <option name="CHANGED_PATHS">
       <list>
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-        <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/SettingsMoreActivity.java" />
         <option value="$PROJECT_DIR$/app/src/main/res/layout/activity_settings.xml" />
         <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/PreferenceUtils.java" />
         <option value="$PROJECT_DIR$/app/src/main/res/values/aboutlibraries_description.xml" />
@@ -1900,12 +1873,9 @@
         <option value="$PROJECT_DIR$/app/src/main/res/layout/activity_exam.xml" />
         <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/CustomApplication.java" />
         <option value="$PROJECT_DIR$/app/libs/mta-android-stat-sdk-2.2.0_20160504.jar!/com/tencent/stat/aa.class" />
-        <option value="$PROJECT_DIR$/app/src/main/res/xml/settings_general.xml" />
-        <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/SettingsActivity.java" />
         <option value="$PROJECT_DIR$/app/src/main/res/layout/activity_acid.xml" />
         <option value="$PROJECT_DIR$/app/src/main/res/values/acid.xml" />
         <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/CardsAdapter.java" />
-        <option value="$PROJECT_DIR$/app/src/main/res/values/strings.xml" />
         <option value="$PROJECT_DIR$/app/src/main/res/layout/activity_share_all.xml" />
         <option value="$PROJECT_DIR$/app/src/main/res/layout/content_share_all.xml" />
         <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/app/BaseActivity.java" />
@@ -1914,15 +1884,20 @@
         <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/app/SocialSDKApplication.java" />
         <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/WBShareActivity.java" />
         <option value="$PROJECT_DIR$/gradle.properties" />
+        <option value="$PROJECT_DIR$/app/src/main/res/values-zh/strings.xml" />
+        <option value="$PROJECT_DIR$/build.gradle" />
+        <option value="$PROJECT_DIR$/app/src/main/AndroidManifest.xml" />
+        <option value="$PROJECT_DIR$/app/src/main/res/xml/settings_general.xml" />
+        <option value="$PROJECT_DIR$/app/src/main/res/values/strings.xml" />
         <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/App.java" />
-        <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/TitleActivity.java" />
         <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/CardLayoutFragment.java" />
-        <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MassActivity.java" />
         <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MainActivity.java" />
         <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/AcidActivity.java" />
         <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/ExamActivity.java" />
-        <option value="$PROJECT_DIR$/app/src/main/AndroidManifest.xml" />
-        <option value="$PROJECT_DIR$/app/src/main/res/values-zh/strings.xml" />
+        <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/TitleActivity.java" />
+        <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MassActivity.java" />
+        <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/LoginActivity.java" />
+        <option value="$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/SettingsActivity.java" />
         <option value="$PROJECT_DIR$/app/build.gradle" />
       </list>
     </option>
@@ -1992,9 +1967,9 @@
     </navigator>
     <panes>
       <pane id="Scope" />
-      <pane id="AndroidView" />
       <pane id="PackagesPane" />
       <pane id="Scratches" />
+      <pane id="AndroidView" />
       <pane id="ProjectPane">
         <subPane>
           <PATH>
@@ -2092,6 +2067,10 @@
               <option name="myItemId" value="res" />
               <option name="myItemType" value="com.intellij.ide.projectView.impl.nodes.PsiDirectoryNode" />
             </PATH_ELEMENT>
+            <PATH_ELEMENT>
+              <option name="myItemId" value="xml" />
+              <option name="myItemType" value="com.intellij.ide.projectView.impl.nodes.PsiDirectoryNode" />
+            </PATH_ELEMENT>
           </PATH>
           <PATH>
             <PATH_ELEMENT>
@@ -2123,6 +2102,32 @@
               <option name="myItemType" value="com.intellij.ide.projectView.impl.nodes.PsiDirectoryNode" />
             </PATH_ELEMENT>
           </PATH>
+          <PATH>
+            <PATH_ELEMENT>
+              <option name="myItemId" value="Chemical-Tools-for-Android" />
+              <option name="myItemType" value="com.intellij.ide.projectView.impl.nodes.ProjectViewProjectNode" />
+            </PATH_ELEMENT>
+            <PATH_ELEMENT>
+              <option name="myItemId" value="Chemical-Tools-for-Android" />
+              <option name="myItemType" value="com.intellij.ide.projectView.impl.nodes.PsiDirectoryNode" />
+            </PATH_ELEMENT>
+            <PATH_ELEMENT>
+              <option name="myItemId" value="app" />
+              <option name="myItemType" value="com.intellij.ide.projectView.impl.nodes.PsiDirectoryNode" />
+            </PATH_ELEMENT>
+            <PATH_ELEMENT>
+              <option name="myItemId" value="src" />
+              <option name="myItemType" value="com.intellij.ide.projectView.impl.nodes.PsiDirectoryNode" />
+            </PATH_ELEMENT>
+            <PATH_ELEMENT>
+              <option name="myItemId" value="main" />
+              <option name="myItemType" value="com.intellij.ide.projectView.impl.nodes.PsiDirectoryNode" />
+            </PATH_ELEMENT>
+            <PATH_ELEMENT>
+              <option name="myItemId" value="res" />
+              <option name="myItemType" value="com.intellij.ide.projectView.impl.nodes.PsiDirectoryNode" />
+            </PATH_ELEMENT>
+          </PATH>
           <PATH>
             <PATH_ELEMENT>
               <option name="myItemId" value="Chemical-Tools-for-Android" />
@@ -2255,11 +2260,10 @@
     <property name="UI_DESIGNER_EDITOR_MODE.NlPaletteManager-NlEditorPanel.WIDTH" value="297" />
   </component>
   <component name="RecentsManager">
-    <key name="MoveFile.RECENT_KEYS">
-      <recent name="F:\GitHub\Chemical-Tools-for-Android\app\src\main\java" />
-      <recent name="F:\GitHub\Chemical-Tools-for-Android\app\src\main\res\values-en" />
-      <recent name="F:\GitHub\Chemical-Tools-for-Android\app\src\main\res" />
-      <recent name="F:\GitHub\Chemical-Tools-for-Android\app" />
+    <key name="CopyFile.RECENT_KEYS">
+      <recent name="F:\GitHub\Chemical-Tools-for-Android\app\src\main\res\layout" />
+      <recent name="F:\GitHub\Chemical-Tools-for-Android\app\src\main\res\raw" />
+      <recent name="F:\GitHub\Chemical-Tools-for-Android\app\src\main\res\values-zh" />
     </key>
     <key name="MoveClassesOrPackagesDialog.RECENTS_KEY">
       <recent name="com.njzjz.chemicaltools" />
@@ -2272,10 +2276,11 @@
     <key name="android.template.parentActivityClass">
       <recent name="" />
     </key>
-    <key name="CopyFile.RECENT_KEYS">
-      <recent name="F:\GitHub\Chemical-Tools-for-Android\app\src\main\res\layout" />
-      <recent name="F:\GitHub\Chemical-Tools-for-Android\app\src\main\res\raw" />
-      <recent name="F:\GitHub\Chemical-Tools-for-Android\app\src\main\res\values-zh" />
+    <key name="MoveFile.RECENT_KEYS">
+      <recent name="F:\GitHub\Chemical-Tools-for-Android\app\src\main\java" />
+      <recent name="F:\GitHub\Chemical-Tools-for-Android\app\src\main\res\values-en" />
+      <recent name="F:\GitHub\Chemical-Tools-for-Android\app\src\main\res" />
+      <recent name="F:\GitHub\Chemical-Tools-for-Android\app" />
     </key>
   </component>
   <component name="RunManager" selected="Android App.app">
@@ -2864,7 +2869,14 @@
       <option name="project" value="LOCAL" />
       <updated>1475517979677</updated>
     </task>
-    <option name="localTasksCounter" value="21" />
+    <task id="LOCAL-00021" summary="v1.63 重构分享功能">
+      <created>1475599115707</created>
+      <option name="number" value="00021" />
+      <option name="presentableId" value="LOCAL-00021" />
+      <option name="project" value="LOCAL" />
+      <updated>1475599115708</updated>
+    </task>
+    <option name="localTasksCounter" value="22" />
     <servers />
   </component>
   <component name="ToolWindowManager">
@@ -2873,26 +2885,26 @@
     <layout>
       <window_info id="Nl-Palette" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="3" side_tool="false" content_ui="tabs" />
       <window_info id="Build Variants" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.32980332" sideWeight="0.5" order="5" side_tool="true" content_ui="tabs" />
-      <window_info id="Event Log" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.19791667" sideWeight="0.57359636" order="11" side_tool="true" content_ui="tabs" />
-      <window_info id="Android Monitor" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.3298611" sideWeight="0.48167938" order="12" side_tool="false" content_ui="tabs" />
+      <window_info id="Event Log" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.114583336" sideWeight="0.5060698" order="11" side_tool="true" content_ui="tabs" />
+      <window_info id="Android Monitor" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.3298611" sideWeight="0.4757208" order="12" side_tool="false" content_ui="tabs" />
       <window_info id="Properties" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="3" side_tool="false" content_ui="tabs" />
       <window_info id="Capture Tool" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="6" side_tool="false" content_ui="tabs" />
       <window_info id="Designer" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="8" side_tool="false" content_ui="tabs" />
       <window_info id="Structure" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.24962178" sideWeight="0.5" order="1" side_tool="false" content_ui="tabs" />
       <window_info id="Android Model" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="10" side_tool="true" content_ui="tabs" />
-      <window_info id="Debug" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.19791667" sideWeight="0.37025797" order="8" side_tool="false" content_ui="tabs" />
+      <window_info id="Debug" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.25520834" sideWeight="0.54021245" order="8" side_tool="false" content_ui="tabs" />
       <window_info id="TODO" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="17" side_tool="false" content_ui="tabs" />
-      <window_info id="Messages" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.30208334" sideWeight="0.42640364" order="13" side_tool="false" content_ui="tabs" />
+      <window_info id="Messages" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.30208334" sideWeight="0.46282247" order="13" side_tool="false" content_ui="tabs" />
       <window_info id="Palette&#9;" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="8" side_tool="false" content_ui="tabs" />
       <window_info id="Image Layers" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="4" side_tool="false" content_ui="tabs" />
       <window_info id="Capture Analysis" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="9" side_tool="false" content_ui="tabs" />
-      <window_info id="Preview" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.32980332" sideWeight="0.5" order="1" side_tool="false" content_ui="tabs" />
-      <window_info id="Run" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.32649574" sideWeight="0.4317147" order="7" side_tool="false" content_ui="tabs" />
+      <window_info id="Run" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.3263889" sideWeight="0.40515932" order="7" side_tool="false" content_ui="tabs" />
       <window_info id="Version Control" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.32649574" sideWeight="0.49092284" order="15" side_tool="false" content_ui="tabs" />
       <window_info id="Terminal" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.32991454" sideWeight="0.5" order="14" side_tool="false" content_ui="tabs" />
       <window_info id="Captures" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.24962178" sideWeight="0.5" order="2" side_tool="false" content_ui="tabs" />
       <window_info id="Gradle Console" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.3948718" sideWeight="0.5030257" order="16" side_tool="true" content_ui="tabs" />
-      <window_info id="Project" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.24430956" sideWeight="0.5" order="0" side_tool="false" content_ui="combo" />
+      <window_info id="Project" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.24127465" sideWeight="0.5" order="0" side_tool="false" content_ui="combo" />
+      <window_info id="Find" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.114583336" sideWeight="0.4939302" order="6" side_tool="false" content_ui="tabs" />
       <window_info id="Gradle" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="7" side_tool="false" content_ui="tabs" />
       <window_info id="Theme Preview" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="4" side_tool="false" content_ui="tabs" />
       <window_info id="Favorites" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.32980332" sideWeight="0.5" order="7" side_tool="true" content_ui="tabs" />
@@ -2905,9 +2917,9 @@
       <window_info id="Ant Build" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.25" sideWeight="0.5" order="5" side_tool="false" content_ui="tabs" />
       <window_info id="调试" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.34358975" sideWeight="0.4969743" order="1" side_tool="false" content_ui="tabs" />
       <window_info id="Inspection" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.4" sideWeight="0.5" order="10" side_tool="false" content_ui="tabs" />
+      <window_info id="Preview" active="false" anchor="right" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.32980332" sideWeight="0.5" order="1" side_tool="false" content_ui="tabs" />
       <window_info id="消息" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.32991454" sideWeight="0.49092284" order="2" side_tool="false" content_ui="tabs" />
       <window_info id="运行" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.32991454" sideWeight="0.4924357" order="3" side_tool="false" content_ui="tabs" />
-      <window_info id="Find" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.11478261" sideWeight="0.4969743" order="6" side_tool="false" content_ui="tabs" />
       <window_info id="找到" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.32991454" sideWeight="0.5" order="4" side_tool="false" content_ui="tabs" />
     </layout>
     <layout-to-restore>
@@ -2982,11 +2994,12 @@
     <MESSAGE value="v1.60 fix a bug" />
     <MESSAGE value="v1.61 酸碱计算功能①录入了一些常见物质的pKa/pKb，再也不用自己记了 ②修复了未考虑水的拉平效应的bug" />
     <MESSAGE value="v1.62 ①元素查询功能加入维基百科链接②质量计算和酸碱计算功能中的化学式可以显示上标和下标了" />
-    <option name="LAST_COMMIT_MESSAGE" value="v1.62 ①元素查询功能加入维基百科链接②质量计算和酸碱计算功能中的化学式可以显示上标和下标了" />
+    <MESSAGE value="v1.63 重构分享功能" />
+    <option name="LAST_COMMIT_MESSAGE" value="v1.63 重构分享功能" />
   </component>
   <component name="XDebuggerManager">
     <breakpoint-manager>
-      <option name="time" value="307" />
+      <option name="time" value="370" />
     </breakpoint-manager>
     <watches-manager>
       <configuration name="app">
@@ -3012,6 +3025,10 @@
         <watch expression="historyAcidOutput" />
         <watch expression="historyAcidOutput" />
         <watch expression="historyAcidOutput" />
+        <watch expression="mEmail" />
+        <watch expression="mPassword" />
+        <watch expression="e1" />
+        <watch expression="loginsuccess[0]" />
       </configuration>
       <configuration name="MainActivity">
         <watch expression="elementInput" />
@@ -3019,28 +3036,6 @@
     </watches-manager>
   </component>
   <component name="editorHistoryManager">
-    <entry file="file://$PROJECT_DIR$/app/src/main/res/drawable/selectable_background.xml">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="133">
-          <caret line="7" column="11" selection-start-line="7" selection-start-column="11" selection-end-line="7" selection-end-column="11" />
-        </state>
-      </provider>
-    </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/res/drawable/shadow_drawable.xml">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="133">
-          <caret line="7" column="8" selection-start-line="7" selection-start-column="8" selection-end-line="7" selection-end-column="8" />
-        </state>
-      </provider>
-    </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/res/values/settings_pref.xml">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="19">
-          <caret line="47" column="0" selection-start-line="47" selection-start-column="0" selection-end-line="47" selection-end-column="0" />
-          <folding />
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-      </provider>
-    </entry>
     <entry file="file://$PROJECT_DIR$/app/src/main/res/drawable/ic_menu_share.png">
       <provider selected="true" editor-type-id="images">
         <state />
@@ -3069,7 +3064,6 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="212">
           <caret line="17" column="15" selection-start-line="17" selection-start-column="15" selection-end-line="17" selection-end-column="15" />
-          <folding />
         </state>
       </provider>
       <provider editor-type-id="android-designer2">
@@ -3114,14 +3108,6 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/build.gradle">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="0">
-          <caret line="0" column="0" selection-start-line="0" selection-start-column="0" selection-end-line="0" selection-end-column="0" />
-          <folding />
-        </state>
-      </provider>
-    </entry>
     <entry file="file://$PROJECT_DIR$/app/src/main/res/layout/activity_exam.xml">
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="209">
@@ -3137,35 +3123,6 @@
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="0">
           <caret line="0" column="0" selection-start-line="0" selection-start-column="0" selection-end-line="0" selection-end-column="0" />
-          <folding />
-        </state>
-      </provider>
-      <provider editor-type-id="android-designer2">
-        <state />
-      </provider>
-    </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/SettingsActivity.java">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="304">
-          <caret line="151" column="54" selection-start-line="151" selection-start-column="54" selection-end-line="151" selection-end-column="54" />
-          <folding>
-            <element signature="e#6738#7443#0" expanded="false" />
-            <element signature="e#7442#7443#0" expanded="false" />
-            <element signature="e#7875#8514#0" expanded="false" />
-            <element signature="e#8513#8514#0" expanded="false" />
-          </folding>
-        </state>
-      </provider>
-    </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/res/xml/settings_general.xml">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="302">
-          <caret line="21" column="29" selection-start-line="21" selection-start-column="29" selection-end-line="21" selection-end-column="29" />
-          <folding>
-            <element signature="e#1029#1064#0" expanded="false" />
-            <element signature="e#1131#1152#0" expanded="false" />
-            <element signature="e#2414#2439#0" expanded="false" />
-          </folding>
         </state>
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@@ -3229,19 +3185,6 @@
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@@ -3264,223 +3207,237 @@
         <state />
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-    <entry file="file://$PROJECT_DIR$/app/src/main/res/layout/activity_share_all.xml">
+    <entry file="file://$PROJECT_DIR$/app/src/main/res/layout/activity_share_all.xml" />
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/app/BaseActivity.java" />
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/ShareAllActivity.java" />
+    <entry file="file://$PROJECT_DIR$/app/src/main/res/layout/content_share_all.xml" />
+    <entry file="file://$PROJECT_DIR$/app/src/main/res/layout/activity_share_all.xml" />
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/app/SocialSDKApplication.java" />
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/WBShareActivity.java" />
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     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/app/BaseActivity.java">
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     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/ShareAllActivity.java">
+    <entry file="file://E:/Android/sdk1/sources/android-23/android/content/res/TypedArray.java">
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     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/res/layout/content_share_all.xml">
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     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/res/layout/activity_share_all.xml">
+    <entry file="file://$PROJECT_DIR$/app/src/main/res/values-zh/strings.xml">
       <provider selected="true" editor-type-id="text-editor">
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     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/app/SocialSDKApplication.java">
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-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/WBShareActivity.java">
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     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/wxapi/WXEntryActivity.java">
+    <entry file="file://$PROJECT_DIR$/app/src/main/res/values/array.xml">
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     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/CardsAdapter.java">
+    <entry file="jar://$USER_HOME$/.gradle/caches/modules-2/files-2.1/cn.leancloud.android/avoscloud-sdk/v3.14.4/956ddd9b6d98ff5235326c2993f5caa796eee68c/avoscloud-sdk-v3.14.4.jar!/com/avos/avoscloud/SignUpCallback.class">
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-    <entry file="file://E:/Android/sdk1/sources/android-23/android/content/res/TypedArray.java">
+    <entry file="file://$PROJECT_DIR$/app/src/main/res/values/strings.xml">
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           <folding />
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     </entry>
-    <entry file="file://$PROJECT_DIR$/gradle.properties">
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/CardLayoutFragment.java">
       <provider selected="true" editor-type-id="text-editor">
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         </state>
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     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/App.java">
+    <entry file="android-dummy://F:/GitHub/Chemical-Tools-for-Android//app/Translations Editor">
+      <provider selected="true" editor-type-id="string-resource-editor">
+        <state />
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/app/src/main/AndroidManifest.xml">
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           <folding>
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+            <marker date="1475656370825" expanded="true" signature="4616:4635" ph="..." />
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         </state>
       </provider>
+      <provider editor-type-id="android-manifest">
+        <state />
+      </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/CardLayoutFragment.java">
+    <entry file="file://$PROJECT_DIR$/app/src/main/res/xml/settings_general.xml">
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         <state relative-caret-position="228">
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           <folding>
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+            <element signature="e#388#410#0" expanded="false" />
+            <element signature="e#658#695#0" expanded="false" />
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+      <provider editor-type-id="android-designer2">
+        <state />
+      </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/res/values/array.xml">
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/App.java">
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     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MainActivity.java">
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/TitleActivity.java">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="323">
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             <element signature="imports" expanded="true" />
+            <element signature="e#3508#6769#0" expanded="true" />
+            <element signature="e#6768#6769#0" expanded="true" />
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     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/AcidActivity.java">
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/ExamActivity.java">
       <provider selected="true" editor-type-id="text-editor">
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           <folding>
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-            <marker date="1475596408715" expanded="false" signature="15931:15959" ph="&quot;Chemical Tools&quot;" />
+            <element signature="e#1603#3185#0" expanded="true" />
+            <element signature="e#3184#3185#0" expanded="true" />
+            <element signature="e#7776#7831#0" expanded="true" />
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+            <marker date="1475675569466" expanded="true" signature="16376:16404" ph="&quot;Chemical Tools&quot;" />
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       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/TitleActivity.java">
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MainActivity.java">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="285">
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-            <marker date="1475596117518" expanded="false" signature="8709:8737" ph="&quot;Chemical Tools&quot;" />
+            <element signature="e#6469#7610#0" expanded="true" />
+            <element signature="e#7609#7610#0" expanded="true" />
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     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/ExamActivity.java">
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/AcidActivity.java">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="285">
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-            <marker date="1475596958376" expanded="true" signature="13883:13911" ph="&quot;Chemical Tools&quot;" />
+            <element signature="imports" expanded="true" />
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+            <marker date="1475675569451" expanded="false" signature="17138:17166" ph="&quot;Chemical Tools&quot;" />
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       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/AndroidManifest.xml">
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MassActivity.java">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="95">
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-        <state />
-      </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/res/values-zh/strings.xml">
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/LoginActivity.java">
       <provider selected="true" editor-type-id="text-editor">
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+            <element signature="e#15781#15782#0" expanded="true" />
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     </entry>
-    <entry file="file://$PROJECT_DIR$/app/build.gradle">
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/SettingsActivity.java">
       <provider selected="true" editor-type-id="text-editor">
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+            <element signature="e#2790#2791#0" expanded="true" />
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         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/com/njzjz/chemicaltools/MassActivity.java">
+    <entry file="file://$PROJECT_DIR$/app/build.gradle">
       <provider selected="true" editor-type-id="text-editor">
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diff --git a/app/app.iml b/app/app.iml
index f7d162b..c209408 100644
--- a/app/app.iml
+++ b/app/app.iml
@@ -66,14 +66,6 @@
       <sourceFolder url="file://$MODULE_DIR$/src/main/jni" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/rs" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/shaders" isTestSource="false" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/res" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/resources" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/assets" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/aidl" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/java" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/jni" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/rs" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/shaders" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/res" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/resources" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/assets" type="java-test-resource" />
@@ -82,9 +74,16 @@
       <sourceFolder url="file://$MODULE_DIR$/src/test/jni" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/rs" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/shaders" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/res" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/resources" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/assets" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/aidl" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/java" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/jni" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/rs" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/shaders" isTestSource="true" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/assets" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/blame" />
-      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/builds" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/classes" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/dependency-cache" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/com.android.support/animated-vector-drawable/23.4.0/jars" />
@@ -125,6 +124,7 @@
     <orderEntry type="library" exported="" name="okio-1.6.0" level="project" />
     <orderEntry type="library" exported="" name="mid-sdk-2.3" level="project" />
     <orderEntry type="library" exported="" name="SocialSDK_umengsina" level="project" />
+    <orderEntry type="library" exported="" name="fastjson-1.1.39-leancloud" level="project" />
     <orderEntry type="library" exported="" name="animated-vector-drawable-23.4.0" level="project" />
     <orderEntry type="library" exported="" name="umeng_social_netv6.0.0" level="project" />
     <orderEntry type="library" exported="" name="support-v4-23.4.0" level="project" />
@@ -133,11 +133,14 @@
     <orderEntry type="library" exported="" name="SocialSDK_WeiXin_2" level="project" />
     <orderEntry type="library" exported="" name="SocialSDK_QQZone_3" level="project" />
     <orderEntry type="library" exported="" name="support-vector-drawable-23.4.0" level="project" />
+    <orderEntry type="library" exported="" name="okhttp-2.6.0-leancloud" level="project" />
     <orderEntry type="library" exported="" name="appcompat-v7-23.4.0" level="project" />
     <orderEntry type="library" exported="" name="design-23.4.0" level="project" />
     <orderEntry type="library" exported="" name="umeng_social_apiv6.0.0" level="project" />
+    <orderEntry type="library" exported="" name="avoscloud-sdk-v3.14.4" level="project" />
     <orderEntry type="library" exported="" name="SocialSDK_umengwx" level="project" />
     <orderEntry type="library" exported="" name="SocialSDK_umengqq" level="project" />
+    <orderEntry type="library" exported="" name="okio-1.6.0-leancloud" level="project" />
     <orderEntry type="library" exported="" name="ldrawer-0.1" level="project" />
     <orderEntry type="library" exported="" name="umeng_social_viewv6.0.0" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="hamcrest-core-1.3" level="project" />
diff --git a/app/build.gradle b/app/build.gradle
index b94b9b7..a7a335c 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -9,8 +9,8 @@ android {
         applicationId "com.njzjz.chemicaltools"
         minSdkVersion 15
         targetSdkVersion 23
-        versionCode 21
-        versionName "1.63"
+        versionCode 22
+        versionName "1.64"
     }
     buildTypes {
         release {
@@ -18,6 +18,13 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+    packagingOptions{
+        exclude 'META-INF/LICENSE.txt'
+        exclude 'META-INF/NOTICE.txt'
+    }
+    lintOptions {
+        abortOnError false
+    }
 }
 
 dependencies {
@@ -42,5 +49,8 @@ dependencies {
     compile files('libs/umeng_social_apiv6.0.0.jar')
     compile files('libs/umeng_social_netv6.0.0.jar')
     compile files('libs/umeng_social_viewv6.0.0.jar')
+    compile ('com.android.support:support-v4:21.0.3')
+    // LeanCloud 基础包
+    compile ('cn.leancloud.android:avoscloud-sdk:v3.+')
 
 }
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 9ab9ea9..dfbd191 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -22,17 +22,18 @@
     <uses-permission android:name="android.permission.GET_ACCOUNTS" />
     <uses-permission android:name="android.permission.USE_CREDENTIALS" />
     <uses-permission android:name="android.permission.MANAGE_ACCOUNTS" />
+    <uses-permission android:name="android.permission.READ_PROFILE" />
+    <uses-permission android:name="android.permission.READ_CONTACTS" />
 
     <application
+        android:name=".App"
         android:allowBackup="true"
         android:icon="@drawable/ic_launcher"
         android:label="@string/app_name"
         android:supportsRtl="true"
         android:theme="@style/AppTheme"
         android:versionCode="4"
-        android:versionName="1.3"
-        android:name=".App"
-        >
+        android:versionName="1.3">
         <activity android:name=".TitleActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
@@ -40,16 +41,21 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
-        <activity android:name=".MainActivity"
-            android:label="@string/button_element"/>
-        <activity android:name=".MassActivity"
-            android:label="@string/button_mass"/>
-        <activity android:name=".AcidActivity"
-            android:label="@string/button_acid"/>
-        <activity android:name=".ExamActivity"
-            android:label="@string/button_exam"/>
-        <activity android:name=".SettingsActivity"
-            android:label="@string/button_Settings"/>
+        <activity
+            android:name=".MainActivity"
+            android:label="@string/button_element" />
+        <activity
+            android:name=".MassActivity"
+            android:label="@string/button_mass" />
+        <activity
+            android:name=".AcidActivity"
+            android:label="@string/button_acid" />
+        <activity
+            android:name=".ExamActivity"
+            android:label="@string/button_exam" />
+        <activity
+            android:name=".SettingsActivity"
+            android:label="@string/button_Settings" />
         <!-- 请将value改为MTA分配的appkey < -->
         <meta-data
             android:name="TA_APPKEY"
@@ -69,7 +75,7 @@
         <activity
             android:name="com.tencent.tauth.AuthActivity"
             android:launchMode="singleTask"
-            android:noHistory="true" >
+            android:noHistory="true">
             <intent-filter>
                 <action android:name="android.intent.action.VIEW" />
 
@@ -81,18 +87,21 @@
         </activity>
         <activity
             android:name="com.tencent.connect.common.AssistActivity"
+            android:configChanges="orientation|keyboardHidden|screenSize"
             android:screenOrientation="portrait"
-            android:theme="@android:style/Theme.Translucent.NoTitleBar"
-            android:configChanges="orientation|keyboardHidden|screenSize"/>
+            android:theme="@android:style/Theme.Translucent.NoTitleBar" />
         <activity
             android:name="com.umeng.socialize.editorpage.ShareActivity"
-            android:theme="@style/Theme.UMDefault"
             android:excludeFromRecents="true"
-            />
+            android:theme="@style/Theme.UMDefault" />
+
         <meta-data
             android:name="UMENG_APPKEY"
-            android:value="57f39f45e0f55a55be0043f3" >
-        </meta-data>
+            android:value="57f39f45e0f55a55be0043f3"></meta-data>
+
+        <activity
+            android:name=".LoginActivity"
+            android:label="@string/title_activity_login"></activity>
     </application>
 
 </manifest>
\ No newline at end of file
diff --git a/app/src/main/java/com/njzjz/chemicaltools/AcidActivity.java b/app/src/main/java/com/njzjz/chemicaltools/AcidActivity.java
index 8142dc1..35f803b 100644
--- a/app/src/main/java/com/njzjz/chemicaltools/AcidActivity.java
+++ b/app/src/main/java/com/njzjz/chemicaltools/AcidActivity.java
@@ -26,6 +26,10 @@
 import android.widget.Switch;
 import android.widget.TextView;
 
+import com.avos.avoscloud.AVException;
+import com.avos.avoscloud.AVObject;
+import com.avos.avoscloud.AVUser;
+import com.avos.avoscloud.GetCallback;
 import com.mikepenz.aboutlibraries.Libs;
 import com.tencent.stat.StatService;
 import com.umeng.socialize.ShareAction;
@@ -155,6 +159,11 @@ public void onClick(View v) {
                         TextView acidTextview = (TextView) findViewById(R.id.acidTextview);
                         acidTextview.setText(Html.fromHtml(parseContent(acidOutput)));
                         PreferenceUtils.setPrefString(getApplicationContext(),"historyAcidOutput",acidOutput);
+                        AVUser currentUser = AVUser.getCurrentUser();
+                        if (currentUser != null) {
+                            AVUser.getCurrentUser().put("historyAcidOutput", acidOutput);
+                            AVUser.getCurrentUser().saveInBackground();
+                        }
                     }else Snackbar.make(v, getResources().getString(R.string.error_name), Snackbar.LENGTH_LONG)
                             .setAction("Error", null).show();
                 }else Snackbar.make(v, getResources().getString(R.string.error_name), Snackbar.LENGTH_LONG)
@@ -162,6 +171,19 @@ public void onClick(View v) {
                 InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
                 imm.hideSoftInputFromWindow(AcidActivity.this.getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
             }});
+        AVUser currentUser = AVUser.getCurrentUser();
+        if (currentUser != null) {
+            // 有
+            AVUser.getCurrentUser().fetchIfNeededInBackground(new GetCallback<AVObject>() {
+                @Override
+                public void done(AVObject avObject, AVException e) {
+                    // 调用 fetchIfNeededInBackground 和 refreshInBackground 效果是一样的。
+                    String historyAcidOutput=avObject.getString("historyAcidOutput");
+                    String pKw=avObject.getString("pKw");
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyAcidOutput",historyAcidOutput);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"pKw",pKw);
+                }});
+        }
         final EditText acidText_c = (EditText) findViewById(R.id.acidText_c);
         final TextView acidTextview=(TextView) findViewById(R.id.acidTextview);
         acidText_c.setOnEditorActionListener(new TextView.OnEditorActionListener() {
@@ -323,7 +345,7 @@ public boolean onOptionsItemSelected(MenuItem item) {
              //   startActivity(Intent.createChooser(share,
              //           getString(R.string.app_name)));
                 new ShareAction(this).withText(acidTextview.getText().toString())
-                        .setDisplayList(/*SHARE_MEDIA.QQ,*/SHARE_MEDIA.QZONE,SHARE_MEDIA.WEIXIN,SHARE_MEDIA.WEIXIN_CIRCLE,/*SHARE_MEDIA.SINA,*/SHARE_MEDIA.SMS,SHARE_MEDIA.EMAIL,SHARE_MEDIA.MORE)
+                        .setDisplayList(/*SHARE_MEDIA.QQ,*/SHARE_MEDIA.QZONE,SHARE_MEDIA.WEIXIN,SHARE_MEDIA.WEIXIN_CIRCLE,SHARE_MEDIA.WEIXIN_FAVORITE,/*SHARE_MEDIA.SINA,*/SHARE_MEDIA.SMS,SHARE_MEDIA.EMAIL,SHARE_MEDIA.MORE)
                         .open();
                 return true;
             case R.id.action_settings:
diff --git a/app/src/main/java/com/njzjz/chemicaltools/App.java b/app/src/main/java/com/njzjz/chemicaltools/App.java
index 98775dc..55d51ca 100644
--- a/app/src/main/java/com/njzjz/chemicaltools/App.java
+++ b/app/src/main/java/com/njzjz/chemicaltools/App.java
@@ -2,6 +2,7 @@
 
 import android.app.Application;
 
+import com.avos.avoscloud.AVOSCloud;
 import com.sangbo.autoupdate.CheckVersion;
 import com.tencent.stat.MtaSDkException;
 import com.tencent.stat.StatService;
@@ -18,7 +19,7 @@ public class App extends Application {
 
         PlatformConfig.setWeixin("wxce20db4ddce39c01", "7f42598bfdbfb74be4eaa121baef6746");
         PlatformConfig.setSinaWeibo("3921700954", "04b48b094faeb16683c32669824ebdad");
-       PlatformConfig.setQQZone("100424468", "c7394704798a158208a74ab60104f0ba");
+        PlatformConfig.setQQZone("1105651247", "P4CtQZJ1Sb5wRKus");
     }
     @Override
     public void onCreate() {
@@ -26,6 +27,10 @@ public void onCreate() {
         UMShareAPI.get(this);
         Config.REDIRECT_URL = "http://sns.whalecloud.com/sina2/callback";
         String appkey = "A55JRMC53SPT";
+
+        // 初始化参数依次为 this, AppId, AppKey
+        AVOSCloud.initialize(this,"wUzGKF5dp34OqCeaI0VwVG8E-gzGzoHsz","QiyXtJjBHFJCIVYQRbrKFiB7");
+
         // 在startStatService之前调用StatConfig配置类接口，使得MTA配置及时生效
         // 初始化并启动MTA
         // 第三方SDK必须按以下代码初始化MTA，其中appkey为规定的格式或MTA分配的代码。
diff --git a/app/src/main/java/com/njzjz/chemicaltools/CardLayoutFragment.java b/app/src/main/java/com/njzjz/chemicaltools/CardLayoutFragment.java
index f16df42..a1debb1 100644
--- a/app/src/main/java/com/njzjz/chemicaltools/CardLayoutFragment.java
+++ b/app/src/main/java/com/njzjz/chemicaltools/CardLayoutFragment.java
@@ -114,7 +114,7 @@ public void onClick(View v) {
                             if(!historyElementOutput.equals(getResources().getString(R.string.button_notUsed))){
                                 x=itemText.getText().toString();
                             }else{
-                                x=getString(R.string.app_name)+"\nhttps://github.com/njzjz/Chemical-Tools-for-Android";
+                                x=getString(R.string.app_name)+"\nhttps://chem.njzjz.win/";
                             }
                             break;
                         case 4:
@@ -123,7 +123,7 @@ public void onClick(View v) {
                                 double examCorrectPercent=(double)examCorrectNumber/sum*100;
                                 x=String.format(getResources().getString(R.string.examScoreOutput_name),sum,examCorrectNumber,examCorrectPercent);
                             }else {
-                                x=getString(R.string.app_name)+"\nhttps://github.com/njzjz/Chemical-Tools-for-Android";
+                                x=getString(R.string.app_name)+"\nhttps://chem.njzjz.win/";
                             }
                             break;
                     }
@@ -136,7 +136,7 @@ public void onClick(View v) {
                    // startActivity(Intent.createChooser(share,
                    //         getString(R.string.app_name)));
                     new ShareAction(getActivity()).withText(x)
-                            .setDisplayList(/*SHARE_MEDIA.QQ,*/SHARE_MEDIA.QZONE,SHARE_MEDIA.WEIXIN,SHARE_MEDIA.WEIXIN_CIRCLE,/*SHARE_MEDIA.SINA,*/SHARE_MEDIA.SMS,SHARE_MEDIA.EMAIL,SHARE_MEDIA.MORE)
+                            .setDisplayList(/*SHARE_MEDIA.QQ,*/SHARE_MEDIA.QZONE,SHARE_MEDIA.WEIXIN,SHARE_MEDIA.WEIXIN_CIRCLE,SHARE_MEDIA.WEIXIN_FAVORITE,/*SHARE_MEDIA.SINA,*/SHARE_MEDIA.SMS,SHARE_MEDIA.EMAIL,SHARE_MEDIA.MORE)
                             .open();
                 } else if (v == cardsList.getChildAt(i - cardsList.getFirstVisiblePosition()).findViewById(R.id.list_item_card_button_2)) {
                     // PERFORM ANOTHER ACTION WITH THE ITEM AT POSITION i
diff --git a/app/src/main/java/com/njzjz/chemicaltools/ExamActivity.java b/app/src/main/java/com/njzjz/chemicaltools/ExamActivity.java
index 2e5e1c3..9b32eca 100644
--- a/app/src/main/java/com/njzjz/chemicaltools/ExamActivity.java
+++ b/app/src/main/java/com/njzjz/chemicaltools/ExamActivity.java
@@ -3,7 +3,6 @@
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
-import android.preference.PreferenceManager;
 import android.support.v7.app.ActionBar;
 import android.support.v7.app.AppCompatActivity;
 import android.text.method.ScrollingMovementMethod;
@@ -18,6 +17,10 @@
 import android.widget.RelativeLayout;
 import android.widget.TextView;
 
+import com.avos.avoscloud.AVException;
+import com.avos.avoscloud.AVObject;
+import com.avos.avoscloud.AVUser;
+import com.avos.avoscloud.GetCallback;
 import com.mikepenz.aboutlibraries.Libs;
 import com.tencent.stat.StatService;
 import com.umeng.socialize.ShareAction;
@@ -39,6 +42,33 @@ protected void onCreate(Bundle savedInstanceState) {
         ab.setDisplayShowHomeEnabled(true);
         ab.setDisplayHomeAsUpEnabled(true);
         ab.setHomeButtonEnabled(true);
+
+        AVUser currentUser = AVUser.getCurrentUser();
+        if (currentUser != null) {
+            // 有
+            AVUser.getCurrentUser().fetchIfNeededInBackground(new GetCallback<AVObject>() {
+                @Override
+                public void done(AVObject avObject, AVException e) {
+                    // 调用 fetchIfNeededInBackground 和 refreshInBackground 效果是一样的。
+                    String examCorrectNumber=avObject.getString("examCorrectNumber");
+                    if(examCorrectNumber==null)examCorrectNumber="0";
+                    String examIncorrectnumber=avObject.getString("examIncorrectnumber");
+                    if(examIncorrectnumber==null)examIncorrectnumber="0";
+                    String elementnumber_limit=avObject.getString("elementnumber_limit");
+                    if(elementnumber_limit==null)elementnumber_limit="118";
+                    String examMode=avObject.getString("examMode");
+                    if(examMode==null)examMode="0";
+                    Boolean setting_examOptionMode=avObject.getBoolean("setting_examOptionMode");
+                    if(setting_examOptionMode==null)setting_examOptionMode=false;
+                    PreferenceUtils.setPrefString(getApplicationContext(),"examCorrectNumber",examCorrectNumber);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"examIncorrectnumber",examIncorrectnumber);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"elementnumber_limit",elementnumber_limit);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"examMode",examMode);
+                    PreferenceUtils.setPrefBoolean(getApplicationContext(),"setting_examOptionMode",setting_examOptionMode);
+                }});
+
+        }
+
         TextView mFileContentView = (TextView) findViewById(R.id.examTextview);
         final Button Optionbutton_1=(Button) findViewById(R.id.Optionbutton_1);
         final Button Optionbutton_2=(Button) findViewById(R.id.Optionbutton_2);
@@ -109,10 +139,20 @@ public void onClick(View v) {
                     examTextview.setText(getResources().getString(R.string.examOutputRight_name));
                     examCorrectNumber++;
                     PreferenceUtils.setPrefString(getApplicationContext(),"examCorrectNumber",String.valueOf(examCorrectNumber));
+                    AVUser currentUser = AVUser.getCurrentUser();
+                    if (currentUser != null) {
+                        AVUser.getCurrentUser().put("examCorrectNumber",String.valueOf(examCorrectNumber));
+                        AVUser.getCurrentUser().saveInBackground();
+                    }
                 }else{
                     examTextview.setText(String.format(getResources().getString(R.string.examOutputWrong_name),correctAnswer,examInput,output));
                     examIncorrectnumber++;
                     PreferenceUtils.setPrefString(getApplicationContext(),"examIncorrectnumber",String.valueOf(examIncorrectnumber));
+                    AVUser currentUser = AVUser.getCurrentUser();
+                    if (currentUser != null) {
+                        AVUser.getCurrentUser().put("examIncorrectnumber",String.valueOf(examCorrectNumber));
+                        AVUser.getCurrentUser().saveInBackground();
+                    }
                 }
                 examScoreOutput(examCorrectNumber,examIncorrectnumber);
                 examMode[0] =PreferenceUtils.getPrefString(getApplicationContext(),"examMode","0");
diff --git a/app/src/main/java/com/njzjz/chemicaltools/LoginActivity.java b/app/src/main/java/com/njzjz/chemicaltools/LoginActivity.java
new file mode 100644
index 0000000..cfbb033
--- /dev/null
+++ b/app/src/main/java/com/njzjz/chemicaltools/LoginActivity.java
@@ -0,0 +1,479 @@
+package com.njzjz.chemicaltools;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.annotation.TargetApi;
+import android.app.LoaderManager.LoaderCallbacks;
+import android.content.CursorLoader;
+import android.content.Intent;
+import android.content.Loader;
+import android.content.pm.PackageManager;
+import android.database.Cursor;
+import android.net.Uri;
+import android.os.AsyncTask;
+import android.os.Build;
+import android.os.Bundle;
+import android.provider.ContactsContract;
+import android.support.annotation.NonNull;
+import android.support.design.widget.Snackbar;
+import android.support.v7.app.ActionBar;
+import android.support.v7.app.AppCompatActivity;
+import android.text.TextUtils;
+import android.view.KeyEvent;
+import android.view.MenuItem;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.view.inputmethod.EditorInfo;
+import android.widget.ArrayAdapter;
+import android.widget.AutoCompleteTextView;
+import android.widget.Button;
+import android.widget.EditText;
+import android.widget.TextView;
+
+import com.avos.avoscloud.AVException;
+import com.avos.avoscloud.AVObject;
+import com.avos.avoscloud.AVUser;
+import com.avos.avoscloud.GetCallback;
+import com.avos.avoscloud.LogInCallback;
+import com.avos.avoscloud.SignUpCallback;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static android.Manifest.permission.READ_CONTACTS;
+
+/**
+ * A login screen that offers login via email/password.
+ */
+public class LoginActivity extends AppCompatActivity implements LoaderCallbacks<Cursor> {
+
+    /**
+     * Id to identity READ_CONTACTS permission request.
+     */
+    private static final int REQUEST_READ_CONTACTS = 0;
+
+    /**
+     * A dummy authentication store containing known user names and passwords.
+     * TODO: remove after connecting to a real authentication system.
+     */
+    private static final String[] DUMMY_CREDENTIALS = new String[]{
+            "foo@example.com:hello", "bar@example.com:world"
+    };
+    /**
+     * Keep track of the login task to ensure we can cancel it if requested.
+     */
+    private UserLoginTask mAuthTask = null;
+
+    // UI references.
+    private AutoCompleteTextView mEmailView;
+    private EditText mPasswordView;
+    private View mProgressView;
+    private View mLoginFormView;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_login);
+        ActionBar ab = getSupportActionBar();
+        ab.setDisplayShowHomeEnabled(true);
+        ab.setDisplayHomeAsUpEnabled(true);
+        ab.setHomeButtonEnabled(true);
+
+        // Set up the login form.
+        mEmailView = (AutoCompleteTextView) findViewById(R.id.email);
+        populateAutoComplete();
+
+        mPasswordView = (EditText) findViewById(R.id.password);
+        mPasswordView.setOnEditorActionListener(new TextView.OnEditorActionListener() {
+            @Override
+            public boolean onEditorAction(TextView textView, int id, KeyEvent keyEvent) {
+                if (id == R.id.login || id == EditorInfo.IME_NULL) {
+                    attemptLogin();
+                    return true;
+                }
+                return false;
+            }
+        });
+
+        Button mEmailSignInButton = (Button) findViewById(R.id.email_sign_in_button);
+        mEmailSignInButton.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                attemptLogin();
+            }
+        });
+
+        mLoginFormView = findViewById(R.id.login_form);
+        mProgressView = findViewById(R.id.login_progress);
+    }
+
+    private void populateAutoComplete() {
+        if (!mayRequestContacts()) {
+            return;
+        }
+
+        getLoaderManager().initLoader(0, null, this);
+    }
+
+    private boolean mayRequestContacts() {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
+            return true;
+        }
+        if (checkSelfPermission(READ_CONTACTS) == PackageManager.PERMISSION_GRANTED) {
+            return true;
+        }
+        if (shouldShowRequestPermissionRationale(READ_CONTACTS)) {
+            Snackbar.make(mEmailView, R.string.permission_rationale, Snackbar.LENGTH_INDEFINITE)
+                    .setAction(android.R.string.ok, new View.OnClickListener() {
+                        @Override
+                        @TargetApi(Build.VERSION_CODES.M)
+                        public void onClick(View v) {
+                            requestPermissions(new String[]{READ_CONTACTS}, REQUEST_READ_CONTACTS);
+                        }
+                    });
+        } else {
+            requestPermissions(new String[]{READ_CONTACTS}, REQUEST_READ_CONTACTS);
+        }
+        return false;
+    }
+
+    /**
+     * Callback received when a permissions request has been completed.
+     */
+    @Override
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
+                                           @NonNull int[] grantResults) {
+        if (requestCode == REQUEST_READ_CONTACTS) {
+            if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+                populateAutoComplete();
+            }
+        }
+    }
+
+
+    /**
+     * Attempts to sign in or register the account specified by the login form.
+     * If there are form errors (invalid email, missing fields, etc.), the
+     * errors are presented and no actual login attempt is made.
+     */
+    private void attemptLogin() {
+        if (mAuthTask != null) {
+            return;
+        }
+
+        // Reset errors.
+        mEmailView.setError(null);
+        mPasswordView.setError(null);
+
+        // Store values at the time of the login attempt.
+        String email = mEmailView.getText().toString();
+        String password = mPasswordView.getText().toString();
+
+        boolean cancel = false;
+        View focusView = null;
+
+        // Check for a valid password, if the user entered one.
+        if (!TextUtils.isEmpty(password) && !isPasswordValid(password)) {
+            mPasswordView.setError(getString(R.string.error_invalid_password));
+            focusView = mPasswordView;
+            cancel = true;
+        }
+
+        // Check for a valid email address.
+        if (TextUtils.isEmpty(email)) {
+            mEmailView.setError(getString(R.string.error_field_required));
+            focusView = mEmailView;
+            cancel = true;
+        } else if (!isEmailValid(email)) {
+            mEmailView.setError(getString(R.string.error_invalid_email));
+            focusView = mEmailView;
+            cancel = true;
+        }
+
+        if (cancel) {
+            // There was an error; don't attempt login and focus the first
+            // form field with an error.
+            focusView.requestFocus();
+        } else {
+            // Show a progress spinner, and kick off a background task to
+            // perform the user login attempt.
+            showProgress(true);
+            mAuthTask = new UserLoginTask(email, password);
+            mAuthTask.execute((Void) null);
+        }
+    }
+
+    private boolean isEmailValid(String email) {
+        //TODO: Replace this with your own logic
+        return email.contains("@");
+    }
+
+    private boolean isPasswordValid(String password) {
+        //TODO: Replace this with your own logic
+        return password.length() > 4;
+    }
+
+    /**
+     * Shows the progress UI and hides the login form.
+     */
+    @TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
+    private void showProgress(final boolean show) {
+        // On Honeycomb MR2 we have the ViewPropertyAnimator APIs, which allow
+        // for very easy animations. If available, use these APIs to fade-in
+        // the progress spinner.
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) {
+            int shortAnimTime = getResources().getInteger(android.R.integer.config_shortAnimTime);
+
+            mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
+            mLoginFormView.animate().setDuration(shortAnimTime).alpha(
+                    show ? 0 : 1).setListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
+                }
+            });
+
+            mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
+            mProgressView.animate().setDuration(shortAnimTime).alpha(
+                    show ? 1 : 0).setListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
+                }
+            });
+        } else {
+            // The ViewPropertyAnimator APIs are not available, so simply show
+            // and hide the relevant UI components.
+            mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
+            mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
+        }
+    }
+
+    @Override
+    public Loader<Cursor> onCreateLoader(int i, Bundle bundle) {
+        return new CursorLoader(this,
+                // Retrieve data rows for the device user's 'profile' contact.
+                Uri.withAppendedPath(ContactsContract.Profile.CONTENT_URI,
+                        ContactsContract.Contacts.Data.CONTENT_DIRECTORY), ProfileQuery.PROJECTION,
+
+                // Select only email addresses.
+                ContactsContract.Contacts.Data.MIMETYPE +
+                        " = ?", new String[]{ContactsContract.CommonDataKinds.Email
+                .CONTENT_ITEM_TYPE},
+
+                // Show primary email addresses first. Note that there won't be
+                // a primary email address if the user hasn't specified one.
+                ContactsContract.Contacts.Data.IS_PRIMARY + " DESC");
+    }
+
+    @Override
+    public void onLoadFinished(Loader<Cursor> cursorLoader, Cursor cursor) {
+        List<String> emails = new ArrayList<>();
+        cursor.moveToFirst();
+        while (!cursor.isAfterLast()) {
+            emails.add(cursor.getString(ProfileQuery.ADDRESS));
+            cursor.moveToNext();
+        }
+
+        addEmailsToAutoComplete(emails);
+    }
+
+    @Override
+    public void onLoaderReset(Loader<Cursor> cursorLoader) {
+
+    }
+
+    private void addEmailsToAutoComplete(List<String> emailAddressCollection) {
+        //Create adapter to tell the AutoCompleteTextView what to show in its dropdown list.
+        ArrayAdapter<String> adapter =
+                new ArrayAdapter<>(LoginActivity.this,
+                        android.R.layout.simple_dropdown_item_1line, emailAddressCollection);
+
+        mEmailView.setAdapter(adapter);
+    }
+
+
+    private interface ProfileQuery {
+        String[] PROJECTION = {
+                ContactsContract.CommonDataKinds.Email.ADDRESS,
+                ContactsContract.CommonDataKinds.Email.IS_PRIMARY,
+        };
+
+        int ADDRESS = 0;
+        int IS_PRIMARY = 1;
+    }
+
+    /**
+     * Represents an asynchronous login/registration task used to authenticate
+     * the user.
+     */
+    public class UserLoginTask extends AsyncTask<Void, Void, Boolean> {
+
+        private final String mEmail;
+        private final String mPassword;
+
+        UserLoginTask(String email, String password) {
+            mEmail = email;
+            mPassword = password;
+        }
+
+        @Override
+        protected Boolean doInBackground(Void... params) {
+            // TODO: attempt authentication against a network service.
+            AVUser.logInInBackground(mEmail, mPassword, new LogInCallback<AVUser>() {
+                @Override
+                public void done(AVUser avUser, AVException e1) {
+                    if (e1 == null) {
+                        Intent intent=new Intent();
+                        intent.putExtra("result","1");
+                        setResult(1003,intent);
+                        AVUser.getCurrentUser().fetchIfNeededInBackground(new GetCallback<AVObject>() {
+                            @Override
+                            public void done(AVObject avObject, AVException e) {
+                                // 调用 fetchIfNeededInBackground 和 refreshInBackground 效果是一样的。
+                                String historyElementOutput=avObject.getString("historyElementOutput");
+                                String historyElementOutputHtml=avObject.getString("historyElementOutputHtml");
+                                String historyElementNumber=avObject.getString("historyElementNumber");
+                                if(historyElementNumber==null)historyElementNumber="0";
+                                String historyElement=avObject.getString("historyElement");
+                                String historyMass=avObject.getString("historyMass");
+                                String historyMassOutput=avObject.getString("historyMassOutput");
+                                String historyAcidOutput=avObject.getString("historyAcidOutput");
+                                String examCorrectNumber=avObject.getString("examCorrectNumber");
+                                if(examCorrectNumber==null)examCorrectNumber="0";
+                                String examIncorrectnumber=avObject.getString("examIncorrectnumber");
+                                if(examIncorrectnumber==null)examIncorrectnumber="0";
+                                String elementnumber_limit=avObject.getString("elementnumber_limit");
+                                if(elementnumber_limit==null)elementnumber_limit="118";
+                                String examMode=avObject.getString("examMode");
+                                if(examMode==null)examMode="0";
+                                Boolean setting_examOptionMode=avObject.getBoolean("setting_examOptionMode");
+                                if(setting_examOptionMode==null)setting_examOptionMode=false;
+                                String pKw=avObject.getString("pKw");
+                                if(pKw==null)pKw="14";
+                                PreferenceUtils.setPrefString(getApplicationContext(),"historyElementOutput",historyElementOutput);
+                                PreferenceUtils.setPrefString(getApplicationContext(),"historyElementOutputHtml",historyElementOutputHtml);
+                                PreferenceUtils.setPrefString(getApplicationContext(),"historyElementNumber",historyElementNumber);
+                                PreferenceUtils.setPrefString(getApplicationContext(),"historyElement",historyElement);
+                                PreferenceUtils.setPrefString(getApplicationContext(),"historyMass",historyMass);
+                                PreferenceUtils.setPrefString(getApplicationContext(),"historyMassOutput",historyMassOutput);
+                                PreferenceUtils.setPrefString(getApplicationContext(),"historyAcidOutput",historyAcidOutput);
+                                PreferenceUtils.setPrefString(getApplicationContext(),"examCorrectNumber",examCorrectNumber);
+                                PreferenceUtils.setPrefString(getApplicationContext(),"examIncorrectnumber",examIncorrectnumber);
+                                PreferenceUtils.setPrefString(getApplicationContext(),"elementnumber_limit",elementnumber_limit);
+                                PreferenceUtils.setPrefString(getApplicationContext(),"examMode",examMode);
+                                PreferenceUtils.setPrefBoolean(getApplicationContext(),"setting_examOptionMode",setting_examOptionMode);
+                                PreferenceUtils.setPrefString(getApplicationContext(),"pKw",pKw);
+                            }});
+
+                        finish();
+                        //登陆成功
+                    } else {
+                        AVUser user = new AVUser();// 新建 AVUser 对象实例
+                        user.setUsername(mEmail);// 设置用户名
+                        user.setPassword(mPassword);// 设置密码
+                        user.setEmail(mEmail);// 设置邮箱
+                        user.signUpInBackground(new SignUpCallback() {
+                            @Override
+                            public void done(AVException e2) {
+                                if (e2 == null) {
+                                    // 注册成功
+                                    Intent intent=new Intent();
+                                    intent.putExtra("result","1");
+                                    setResult(1003,intent);
+                                    String historyElementOutput = PreferenceUtils.getPrefString(getApplicationContext(), "historyElementOutput", "");
+                                    String historyElementOutputHtml = PreferenceUtils.getPrefString(getApplicationContext(), "historyElementOutputHtml", "");
+                                    String historyElementNumber = PreferenceUtils.getPrefString(getApplicationContext(), "historyElementNumber", "0");
+                                    String historyElement = PreferenceUtils.getPrefString(getApplicationContext(), "historyElement", "");
+                                    String historyMass = PreferenceUtils.getPrefString(getApplicationContext(), "historyMass", "");
+                                    String historyMassOutput = PreferenceUtils.getPrefString(getApplicationContext(), "historyMassOutput", "");
+                                    String historyAcidOutput = PreferenceUtils.getPrefString(getApplicationContext(), "historyAcidOutput", "");
+                                    String examCorrectNumber=PreferenceUtils.getPrefString(getApplicationContext(),"examCorrectNumber","0");
+                                    String examIncorrectnumber=PreferenceUtils.getPrefString(getApplicationContext(),"examIncorrectnumber","0");
+                                    String elementnumber_limit=PreferenceUtils.getPrefString(getApplicationContext(),"elementnumber_limit","118");
+                                    String examMode=PreferenceUtils.getPrefString(getApplicationContext(),"examMode","0");
+                                    Boolean setting_examOptionMode=PreferenceUtils.getPrefBoolean(getApplicationContext(),"setting_examOptionMode",false);
+                                    String pKw=PreferenceUtils.getPrefString(getApplicationContext(),"pKw","14");
+                                    AVUser.getCurrentUser().put("historyElementOutput", historyElementOutput);
+                                    AVUser.getCurrentUser().put("historyElementOutputHtml", historyElementOutputHtml);
+                                    AVUser.getCurrentUser().put("historyElementNumber", historyElementNumber);
+                                    AVUser.getCurrentUser().put("historyElement", historyElement);
+                                    AVUser.getCurrentUser().put("historyMass", historyMass);
+                                    AVUser.getCurrentUser().put("historyMassOutput", historyMassOutput);
+                                    AVUser.getCurrentUser().put("historyAcidOutput", historyAcidOutput);
+                                    AVUser.getCurrentUser().put("examCorrectNumber", examCorrectNumber);
+                                    AVUser.getCurrentUser().put("examIncorrectnumber", examIncorrectnumber);
+                                    AVUser.getCurrentUser().put("elementnumber_limit", elementnumber_limit);
+                                    AVUser.getCurrentUser().put("examMode", examMode);
+                                    AVUser.getCurrentUser().put("setting_examOptionMode", setting_examOptionMode);
+                                    AVUser.getCurrentUser().put("pKw", pKw);
+                                    AVUser.getCurrentUser().saveInBackground();
+                                    finish();
+                                } else {
+                                    // 失败的原因可能有多种，常见的是用户名已经存在。
+                                    mPasswordView.setError(getString(R.string.error_incorrect_password));
+                                    mPasswordView.requestFocus();
+                                }
+                            }
+                        });
+                    }
+                }
+            });
+
+            /*
+            try {
+                // Simulate network access.
+                Thread.sleep(2000);
+            } catch (InterruptedException e) {
+                return false;
+            }
+*/
+/*
+            for (String credential : DUMMY_CREDENTIALS) {
+                String[] pieces = credential.split(":");
+                if (pieces[0].equals(mEmail)) {
+                    // Account exists, return true if the password matches.
+                    return pieces[1].equals(mPassword);
+                }
+            }
+*/
+            // TODO: register the new account here.
+            return true;
+        }
+
+        @Override
+        protected void onPostExecute(final Boolean success) {
+            mAuthTask = null;
+            showProgress(false);
+/*
+            if (success) {
+                finish();
+            } else {
+                mPasswordView.setError(getString(R.string.error_incorrect_password));
+                mPasswordView.requestFocus();
+            }
+            */
+        }
+
+        @Override
+        protected void onCancelled() {
+            mAuthTask = null;
+            showProgress(false);
+        }
+    }
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        switch (item.getItemId()) {
+            //菜单栏返回键功能
+            case android.R.id.home:
+                Intent intent = new Intent(this, TitleActivity.class);
+                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+                this.finish();
+                return true;
+
+            default:
+                return super.onOptionsItemSelected(item);
+        }
+    }
+}
+
diff --git a/app/src/main/java/com/njzjz/chemicaltools/MainActivity.java b/app/src/main/java/com/njzjz/chemicaltools/MainActivity.java
index e0aa430..dee009f 100644
--- a/app/src/main/java/com/njzjz/chemicaltools/MainActivity.java
+++ b/app/src/main/java/com/njzjz/chemicaltools/MainActivity.java
@@ -28,6 +28,10 @@
 import android.widget.ImageView;
 import android.widget.TextView;
 
+import com.avos.avoscloud.AVException;
+import com.avos.avoscloud.AVObject;
+import com.avos.avoscloud.AVUser;
+import com.avos.avoscloud.GetCallback;
 import com.mikepenz.aboutlibraries.Libs;
 import com.tencent.stat.StatService;
 import com.umeng.socialize.ShareAction;
@@ -84,6 +88,14 @@ public void onClick(View v) {
                     PreferenceUtils.setPrefString(getApplicationContext(),"historyElementOutput",elementOutput);
                     String elementoutputhtml=elementOutput+"\n<a href='https://en.wikipedia.org/wiki/"+elementIUPACArray[elementNumber-1]+"'>"+getResources().getString(R.string.elementWikipedia)+"</a>";
                     PreferenceUtils.setPrefString(getApplicationContext(),"historyElementOutputHtml",elementoutputhtml);
+                    AVUser currentUser = AVUser.getCurrentUser();
+                    if (currentUser != null) {
+                        AVUser.getCurrentUser().put("historyElementOutput", elementOutput);
+                        AVUser.getCurrentUser().put("historyElementOutputHtml", elementoutputhtml);
+                        AVUser.getCurrentUser().put("historyElementNumber", String.valueOf(elementNumber));
+                        AVUser.getCurrentUser().put("historyElement", elementInput);
+                        AVUser.getCurrentUser().saveInBackground();
+                    }
                     elementTextview.setText(Html.fromHtml(parseContent(elementoutputhtml)));
                     TypedArray elementPictureArray = getResources().obtainTypedArray(R.array.elementPictureArray);
                     int  resId = elementPictureArray.getResourceId(elementNumber-1, 0);
@@ -97,6 +109,24 @@ public void onClick(View v) {
                 imm.hideSoftInputFromWindow(MainActivity.this.getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
             };
         });
+        AVUser currentUser = AVUser.getCurrentUser();
+        if (currentUser != null) {
+            // 有
+            currentUser .fetchIfNeededInBackground(new GetCallback<AVObject>() {
+                @Override
+                public void done(AVObject avObject, AVException e) {
+                    // 调用 fetchIfNeededInBackground 和 refreshInBackground 效果是一样的。
+                    String historyElementOutput=avObject.getString("historyElementOutput");
+                    String historyElementOutputHtml=avObject.getString("historyElementOutputHtml");
+                    String historyElementNumber=avObject.getString("historyElementNumber");
+                    if(historyElementNumber==null)historyElementNumber="0";
+                    String historyElement=avObject.getString("historyElement");
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyElementOutput",historyElementOutput);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyElementOutputHtml",historyElementOutputHtml);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyElementNumber",historyElementNumber);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyElement",historyElement);
+                }});
+        }
         final EditText elementText = (EditText) findViewById(R.id.elementText);
         elementText.setOnClickListener(new View.OnClickListener() {
             public void onClick(View v) {
@@ -206,7 +236,7 @@ public boolean onOptionsItemSelected(MenuItem item) {
                     share.withMedia(image);
                 }
                 */
-                share.setDisplayList(/*SHARE_MEDIA.QQ,*/SHARE_MEDIA.QZONE,SHARE_MEDIA.WEIXIN,SHARE_MEDIA.WEIXIN_CIRCLE,/*SHARE_MEDIA.SINA,*/SHARE_MEDIA.SMS,SHARE_MEDIA.EMAIL,SHARE_MEDIA.MORE)
+                share.setDisplayList(/*SHARE_MEDIA.QQ,*/SHARE_MEDIA.QZONE,SHARE_MEDIA.WEIXIN,SHARE_MEDIA.WEIXIN_CIRCLE,SHARE_MEDIA.WEIXIN_FAVORITE,/*SHARE_MEDIA.SINA,*/SHARE_MEDIA.SMS,SHARE_MEDIA.EMAIL,SHARE_MEDIA.MORE)
                      .setCallback(umShareListener).open();
                 return true;
             case R.id.action_settings:
diff --git a/app/src/main/java/com/njzjz/chemicaltools/MassActivity.java b/app/src/main/java/com/njzjz/chemicaltools/MassActivity.java
index 038b0be..82e4b84 100644
--- a/app/src/main/java/com/njzjz/chemicaltools/MassActivity.java
+++ b/app/src/main/java/com/njzjz/chemicaltools/MassActivity.java
@@ -21,6 +21,10 @@
 import android.widget.EditText;
 import android.widget.TextView;
 
+import com.avos.avoscloud.AVException;
+import com.avos.avoscloud.AVObject;
+import com.avos.avoscloud.AVUser;
+import com.avos.avoscloud.GetCallback;
 import com.mikepenz.aboutlibraries.Libs;
 import com.tencent.stat.StatService;
 import com.umeng.socialize.ShareAction;
@@ -202,6 +206,12 @@ else if (calAsc(y1) == 5)
                     massTextview.setText(Html.fromHtml(parseContent(massOutput)));
                     PreferenceUtils.setPrefString(getApplicationContext(),"historyMass",x);
                     PreferenceUtils.setPrefString(getApplicationContext(),"historyMassOutput",massOutput);
+                    AVUser currentUser = AVUser.getCurrentUser();
+                    if (currentUser != null) {
+                        AVUser.getCurrentUser().put("historyMass", x);
+                        AVUser.getCurrentUser().put("historyMassOutput",massOutput);
+                        AVUser.getCurrentUser().saveInBackground();
+                    }
                 } else {
                     Snackbar.make(v, res.getString(R.string.error_name), Snackbar.LENGTH_LONG)
                             .setAction("Error", null).show();
@@ -212,6 +222,20 @@ else if (calAsc(y1) == 5)
 
             ;
         });
+        AVUser currentUser = AVUser.getCurrentUser();
+        if (currentUser != null) {
+            // 有
+            AVUser.getCurrentUser().fetchIfNeededInBackground(new GetCallback<AVObject>() {
+                @Override
+                public void done(AVObject avObject, AVException e) {
+                    // 调用 fetchIfNeededInBackground 和 refreshInBackground 效果是一样的。
+                    String historyMass=avObject.getString("historyMass");
+                    String historyMassOutput=avObject.getString("historyMassOutput");
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyMass",historyMass);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyMassOutput",historyMassOutput);
+                }});
+
+        }
         final EditText massText = (EditText) findViewById(R.id.massText);
         massText.setOnClickListener(new View.OnClickListener() {
             public void onClick(View v) {
@@ -298,7 +322,7 @@ public boolean onOptionsItemSelected(MenuItem item) {
                 //startActivity(Intent.createChooser(share,
                 //        getString(R.string.app_name)));
                 new ShareAction(this).withText(massTextview.getText().toString())
-                        .setDisplayList(/*SHARE_MEDIA.QQ,*/SHARE_MEDIA.QZONE,SHARE_MEDIA.WEIXIN,SHARE_MEDIA.WEIXIN_CIRCLE,/*SHARE_MEDIA.SINA,*/SHARE_MEDIA.SMS,SHARE_MEDIA.EMAIL,SHARE_MEDIA.MORE)
+                        .setDisplayList(/*SHARE_MEDIA.QQ,*/SHARE_MEDIA.QZONE,SHARE_MEDIA.WEIXIN,SHARE_MEDIA.WEIXIN_CIRCLE,SHARE_MEDIA.WEIXIN_FAVORITE,/*SHARE_MEDIA.SINA,*/SHARE_MEDIA.SMS,SHARE_MEDIA.EMAIL,SHARE_MEDIA.MORE)
                         .open();
                 return true;
             case R.id.action_settings:
diff --git a/app/src/main/java/com/njzjz/chemicaltools/SettingsActivity.java b/app/src/main/java/com/njzjz/chemicaltools/SettingsActivity.java
index 35bb9ed..ac2707e 100644
--- a/app/src/main/java/com/njzjz/chemicaltools/SettingsActivity.java
+++ b/app/src/main/java/com/njzjz/chemicaltools/SettingsActivity.java
@@ -13,6 +13,7 @@
 import android.preference.Preference;
 import android.preference.PreferenceFragment;
 import android.preference.PreferenceManager;
+import android.preference.PreferenceScreen;
 import android.support.v7.app.ActionBar;
 import android.support.v7.app.AlertDialog;
 import android.support.v7.app.AppCompatActivity;
@@ -21,6 +22,10 @@
 import android.view.View;
 import android.view.ViewGroup;
 
+import com.avos.avoscloud.AVException;
+import com.avos.avoscloud.AVObject;
+import com.avos.avoscloud.AVUser;
+import com.avos.avoscloud.GetCallback;
 import com.mikepenz.aboutlibraries.Libs;
 import com.sangbo.autoupdate.CheckVersion;
 import com.tencent.stat.StatService;
@@ -35,6 +40,29 @@ protected void onCreate(Bundle savedInstanceState) {
         ab.setDisplayHomeAsUpEnabled(true);
         ab.setHomeButtonEnabled(true);
 
+        AVUser currentUser = AVUser.getCurrentUser();
+        if (currentUser != null) {
+            // 有
+            AVUser.getCurrentUser().fetchIfNeededInBackground(new GetCallback<AVObject>() {
+                @Override
+                public void done(AVObject avObject, AVException e) {
+                    // 调用 fetchIfNeededInBackground 和 refreshInBackground 效果是一样的。
+                    String elementnumber_limit=avObject.getString("elementnumber_limit");
+                    if(elementnumber_limit==null)elementnumber_limit="118";
+                    String examMode=avObject.getString("examMode");
+                    if(examMode==null)examMode="0";
+                    Boolean setting_examOptionMode=avObject.getBoolean("setting_examOptionMode");
+                    if(setting_examOptionMode==null)setting_examOptionMode=false;
+                    String pKw=avObject.getString("pKw");
+                    if(pKw==null)pKw="14";
+                    PreferenceUtils.setPrefString(getApplicationContext(),"elementnumber_limit",elementnumber_limit);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"examMode",examMode);
+                    PreferenceUtils.setPrefBoolean(getApplicationContext(),"setting_examOptionMode",setting_examOptionMode);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"pKw",pKw);
+                }});
+
+        }
+
         PreferenceFragment fragment = new PreferenceFragment() {
             @Override public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                                Bundle savedInstanceState) {
@@ -46,6 +74,31 @@ protected void onCreate(Bundle savedInstanceState) {
             @Override public void onCreate(Bundle savedInstanceState) {
                 super.onCreate(savedInstanceState);
                 addPreferencesFromResource(R.xml.settings_general);
+                findPreference("login").setOnPreferenceClickListener(
+                        new Preference.OnPreferenceClickListener() {
+                            @Override public boolean onPreferenceClick(Preference preference) {
+                                AVUser currentUser = AVUser.getCurrentUser();
+                                if(currentUser !=null){
+                                    AVUser.logOut();// 清除缓存用户对象
+                                    finish();
+                                    Intent intent = new Intent(SettingsActivity.this, SettingsActivity.class);
+                                    startActivity(intent);
+                                }else {
+                                    openLogin();
+                                }
+                                return true;
+                            }
+                        });
+                AVUser currentUser = AVUser.getCurrentUser();
+                PreferenceScreen Login= (PreferenceScreen) findPreference("login");
+                if (currentUser != null) {
+                    // 有
+                    Login.setTitle(getString(R.string.action_sign_out));
+                    Login.setSummary(currentUser.getUsername());
+                } else {
+                    //缓存用户对象为空时，可打开用户注册界面…
+                    Login.setTitle(getString(R.string.action_sign_in));
+                }
                 findPreference("about").setOnPreferenceClickListener(
                         new Preference.OnPreferenceClickListener() {
                             @Override public boolean onPreferenceClick(Preference preference) {
@@ -75,6 +128,11 @@ public boolean onPreferenceChange(Preference preference, Object newValue) {
                                 ListPreference elementnumber_limitList= (ListPreference) findPreference("elementnumber_limit");
                                 String elementnumber_limit=newValue.toString();
                                 PreferenceUtils.setPrefString(getApplicationContext(),"elementnumber_limit",elementnumber_limit);
+                                AVUser currentUser = AVUser.getCurrentUser();
+                                if (currentUser != null) {
+                                    AVUser.getCurrentUser().put("elementnumber_limit", elementnumber_limit);
+                                    AVUser.getCurrentUser().saveInBackground();
+                                }
                                 elementnumber_limitList.setSummary(elementnumber_limit);
                                 Intent intent=new Intent();
                                 intent.putExtra("result","1");
@@ -110,6 +168,11 @@ public boolean onPreferenceChange(Preference preference, Object newValue) {
                                 ListPreference examModeList= (ListPreference) findPreference("examMode");
                                 String examMode=newValue.toString();
                                 PreferenceUtils.setPrefString(getApplicationContext(),"examMode",examMode);
+                                AVUser currentUser = AVUser.getCurrentUser();
+                                if (currentUser != null) {
+                                    AVUser.getCurrentUser().put("examMode", examMode);
+                                    AVUser.getCurrentUser().saveInBackground();
+                                }
                                 examModeList.setSummary(examModeList.getEntries()[Integer.parseInt(examMode)]);
                                 Intent intent=new Intent();
                                 intent.putExtra("result","1");
@@ -128,6 +191,11 @@ public boolean onPreferenceChange(Preference preference, Object newValue) {
                             public boolean onPreferenceChange(Preference preference, Object newValue) {
                                 boolean setting_examOptionMode=Boolean.valueOf(newValue.toString());
                                 PreferenceUtils.setPrefBoolean(getApplicationContext(),"setting_examOptionMode",setting_examOptionMode);
+                                AVUser currentUser = AVUser.getCurrentUser();
+                                if (currentUser != null) {
+                                    AVUser.getCurrentUser().put("setting_examOptionMode", setting_examOptionMode);
+                                    AVUser.getCurrentUser().saveInBackground();
+                                }
                                 Intent intent=new Intent();
                                 intent.putExtra("result","1");
                                 setResult(1001,intent);
@@ -144,6 +212,11 @@ public boolean onPreferenceChange(Preference preference, Object newValue) {
                         String pKw=newValue.toString();
                         if (isNumeric(pKw)) {
                             PreferenceUtils.setPrefString(getApplicationContext(), "pKw", pKw);
+                            AVUser currentUser = AVUser.getCurrentUser();
+                            if (currentUser != null) {
+                                AVUser.getCurrentUser().put("pKw", pKw);
+                                AVUser.getCurrentUser().saveInBackground();
+                            }
                             EditTextPreference pKwEditText = (EditTextPreference) findPreference("pKw");
                             pKwEditText.setSummary(pKw);
                             return true;
@@ -180,7 +253,6 @@ public boolean onOptionsItemSelected(MenuItem item) {
                 intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                 this.finish();
                 return true;
-
             default:
                 return super.onOptionsItemSelected(item);
         }
@@ -196,6 +268,33 @@ private void showSimpleDialog(View view) {
             @Override
             public void onClick(DialogInterface dialogInterface, int i) {
                 PreferenceUtils.clearPreference(getApplicationContext(), PreferenceManager.getDefaultSharedPreferences(getApplicationContext()));
+                String historyElementOutput = PreferenceUtils.getPrefString(getApplicationContext(), "historyElementOutput", "");
+                String historyElementOutputHtml = PreferenceUtils.getPrefString(getApplicationContext(), "historyElementOutputHtml", "");
+                String historyElementNumber = PreferenceUtils.getPrefString(getApplicationContext(), "historyElementNumber", "0");
+                String historyElement = PreferenceUtils.getPrefString(getApplicationContext(), "historyElement", "");
+                String historyMass = PreferenceUtils.getPrefString(getApplicationContext(), "historyMass", "");
+                String historyMassOutput = PreferenceUtils.getPrefString(getApplicationContext(), "historyMassOutput", "");
+                String historyAcidOutput = PreferenceUtils.getPrefString(getApplicationContext(), "historyAcidOutput", "");
+                String examCorrectNumber=PreferenceUtils.getPrefString(getApplicationContext(),"examCorrectNumber","0");
+                String examIncorrectnumber=PreferenceUtils.getPrefString(getApplicationContext(),"examIncorrectnumber","0");
+                String elementnumber_limit=PreferenceUtils.getPrefString(getApplicationContext(),"elementnumber_limit","118");
+                String examMode=PreferenceUtils.getPrefString(getApplicationContext(),"examMode","0");
+                Boolean setting_examOptionMode=PreferenceUtils.getPrefBoolean(getApplicationContext(),"setting_examOptionMode",false);
+                String pKw=PreferenceUtils.getPrefString(getApplicationContext(),"pKw","14");
+                AVUser.getCurrentUser().put("historyElementOutput", historyElementOutput);
+                AVUser.getCurrentUser().put("historyElementOutputHtml", historyElementOutputHtml);
+                AVUser.getCurrentUser().put("historyElementNumber", historyElementNumber);
+                AVUser.getCurrentUser().put("historyElement", historyElement);
+                AVUser.getCurrentUser().put("historyMass", historyMass);
+                AVUser.getCurrentUser().put("historyMassOutput", historyMassOutput);
+                AVUser.getCurrentUser().put("historyAcidOutput", historyAcidOutput);
+                AVUser.getCurrentUser().put("examCorrectNumber", examCorrectNumber);
+                AVUser.getCurrentUser().put("examIncorrectnumber", examIncorrectnumber);
+                AVUser.getCurrentUser().put("elementnumber_limit", elementnumber_limit);
+                AVUser.getCurrentUser().put("examMode", examMode);
+                AVUser.getCurrentUser().put("setting_examOptionMode", setting_examOptionMode);
+                AVUser.getCurrentUser().put("pKw", pKw);
+                AVUser.getCurrentUser().saveInBackground();
                 finish();
                 Intent intent = new Intent(SettingsActivity.this, SettingsActivity.class);
                 startActivity(intent);
@@ -212,4 +311,18 @@ public void onClick(DialogInterface dialogInterface, int i) {
         AlertDialog dialog=builder.create();
         dialog.show();
     }
+    @Override
+    protected void onActivityResult(int requestCode,int resultCode,Intent data){
+        super.onActivityResult(requestCode,resultCode,data);
+        if(requestCode==1002 && resultCode==1003)
+            if(data.getStringExtra("result").equals("1")){
+                finish();
+                Intent intent = new Intent(SettingsActivity.this, SettingsActivity.class);
+                startActivity(intent);
+            }
+    }
+    public void openLogin(){
+        Intent intent =new Intent(this, LoginActivity.class);
+        startActivityForResult(intent,1002);
+    }
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/njzjz/chemicaltools/TitleActivity.java b/app/src/main/java/com/njzjz/chemicaltools/TitleActivity.java
index 74be73c..0b1ebd7 100644
--- a/app/src/main/java/com/njzjz/chemicaltools/TitleActivity.java
+++ b/app/src/main/java/com/njzjz/chemicaltools/TitleActivity.java
@@ -19,6 +19,10 @@
 import android.widget.ArrayAdapter;
 import android.widget.ListView;
 
+import com.avos.avoscloud.AVException;
+import com.avos.avoscloud.AVObject;
+import com.avos.avoscloud.AVUser;
+import com.avos.avoscloud.GetCallback;
 import com.ikimuhendis.ldrawer.ActionBarDrawerToggle;
 import com.ikimuhendis.ldrawer.DrawerArrowDrawable;
 import com.mikepenz.aboutlibraries.Libs;
@@ -53,6 +57,7 @@ protected void onCreate(Bundle savedInstanceState) {
                 String[] mPermissionList = new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.ACCESS_FINE_LOCATION,Manifest.permission.CALL_PHONE,Manifest.permission.READ_LOGS,Manifest.permission.READ_PHONE_STATE, Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.SET_DEBUG_APP,Manifest.permission.SYSTEM_ALERT_WINDOW,Manifest.permission.GET_ACCOUNTS,Manifest.permission.WRITE_APN_SETTINGS};
                 ActivityCompat.requestPermissions(this,mPermissionList,123);
             }
+
             historyElementOutput = PreferenceUtils.getPrefString(getApplicationContext(), "historyElementOutput", "");
             historyMassOutput = PreferenceUtils.getPrefString(getApplicationContext(), "historyMassOutput", "");
             historyAcidOutput = PreferenceUtils.getPrefString(getApplicationContext(), "historyAcidOutput", "");
@@ -62,6 +67,53 @@ protected void onCreate(Bundle savedInstanceState) {
 
             notfirstCreate=true;
         }
+        String loginButton;
+        AVUser currentUser = AVUser.getCurrentUser();
+        if (currentUser != null) {
+            // 有
+            AVUser.getCurrentUser().fetchIfNeededInBackground(new GetCallback<AVObject>() {
+                @Override
+                public void done(AVObject avObject, AVException e) {
+                    // 调用 fetchIfNeededInBackground 和 refreshInBackground 效果是一样的。
+                    String historyElementOutput=avObject.getString("historyElementOutput");
+                    String historyElementOutputHtml=avObject.getString("historyElementOutputHtml");
+                    String historyElementNumber=avObject.getString("historyElementNumber");
+                    if(historyElementNumber==null)historyElementNumber="0";
+                    String historyElement=avObject.getString("historyElement");
+                    String historyMass=avObject.getString("historyMass");
+                    String historyMassOutput=avObject.getString("historyMassOutput");
+                    String historyAcidOutput=avObject.getString("historyAcidOutput");
+                    String examCorrectNumber=avObject.getString("examCorrectNumber");
+                    if(examCorrectNumber==null)examCorrectNumber="0";
+                    String examIncorrectnumber=avObject.getString("examIncorrectnumber");
+                    if(examIncorrectnumber==null)examIncorrectnumber="0";
+                    String elementnumber_limit=avObject.getString("elementnumber_limit");
+                    if(elementnumber_limit==null)elementnumber_limit="118";
+                    String examMode=avObject.getString("examMode");
+                    if(examMode==null)examMode="0";
+                    Boolean setting_examOptionMode=avObject.getBoolean("setting_examOptionMode");
+                    if(setting_examOptionMode==null)setting_examOptionMode=false;
+                    String pKw=avObject.getString("pKw");
+                    if(pKw==null)pKw="14";
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyElementOutput",historyElementOutput);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyElementOutputHtml",historyElementOutputHtml);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyElementNumber",historyElementNumber);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyElement",historyElement);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyMass",historyMass);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyMassOutput",historyMassOutput);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"historyAcidOutput",historyAcidOutput);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"examCorrectNumber",examCorrectNumber);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"examIncorrectnumber",examIncorrectnumber);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"elementnumber_limit",elementnumber_limit);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"examMode",examMode);
+                    PreferenceUtils.setPrefBoolean(getApplicationContext(),"setting_examOptionMode",setting_examOptionMode);
+                    PreferenceUtils.setPrefString(getApplicationContext(),"pKw",pKw);
+                }});
+            loginButton=getString(R.string.action_sign_out);
+        } else {
+            //缓存用户对象为空时，可打开用户注册界面…
+            loginButton=getString(R.string.action_sign_in);
+        }
         ActionBar ab = getSupportActionBar();
         ab.setHomeAsUpIndicator(R.drawable.home);
         ab.setDisplayShowHomeEnabled(true);
@@ -100,6 +152,7 @@ public void onDrawerOpened(View drawerView) {
 
         Resources res = getResources();
         String[] values = new String[]{
+                loginButton,
                 res.getString(R.string.button_element),
                 res.getString(R.string.button_mass),
                 res.getString(R.string.button_acid),
@@ -118,20 +171,20 @@ public void onDrawerOpened(View drawerView) {
             public void onItemClick(AdapterView<?> parent, View view,
                                     int position, long id) {
                 switch (position) {
-                    case 0:
+                    case 1:
                        //Element
                         openElement(view);
                         break;
-                    case 1:
+                    case 2:
                         //Mass
                         openMass(view);
                         break;
-                    case 6:
+                    case 7:
                         //Feedback
                         Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("mailto:njzjz@msn.com?subject=Chemical Tools App Feedback"));
                         startActivity(browserIntent);
                         break;
-                    case 4:
+                    case 5:
                         //Share
                         UMImage image = new UMImage(TitleActivity.this, R.drawable.ic_launcher);//资源文件
                         new ShareAction(TitleActivity.this).withText(getString(R.string.app_name)
@@ -140,26 +193,37 @@ public void onItemClick(AdapterView<?> parent, View view,
                                 .setDisplayList(SHARE_MEDIA.QQ,SHARE_MEDIA.QZONE,SHARE_MEDIA.WEIXIN,SHARE_MEDIA.WEIXIN_CIRCLE,/*SHARE_MEDIA.SINA,*/SHARE_MEDIA.SMS,SHARE_MEDIA.EMAIL,SHARE_MEDIA.MORE)
                                 .open();
                         break;
-                    case 3:
+                    case 4:
                         //Exam
                         openExam(view);
                         break;
-                    case 5:
+                    case 6:
                         //Settings
                         openSettings();
                         break;
-                    case 7:
+                    case 8:
                         //Website
                         startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("http://chem.njzjz.win/")));
                         break;
-                    case 8:
+                    case 9:
                         //About
                         new Libs.Builder().withActivityTitle(getString(R.string.button_About)).withFields(R.string.class.getFields()).start(TitleActivity.this);
                         break;
-                    case 2:
+                    case 3:
                         //acid
                         openAcid(view);
                         break;
+                    case 0:
+                        //Login
+                        AVUser currentUser = AVUser.getCurrentUser();
+                        if(currentUser !=null){
+                            AVUser.logOut();// 清除缓存用户对象
+                            finish();
+                            Intent intent = new Intent(TitleActivity.this, TitleActivity.class);
+                            startActivity(intent);
+                        }else {
+                            openLogin();
+                        }
                 }
 
             }
@@ -167,6 +231,20 @@ public void onItemClick(AdapterView<?> parent, View view,
 
     }
     @Override
+    protected void onActivityResult(int requestCode,int resultCode,Intent data){
+        super.onActivityResult(requestCode,resultCode,data);
+        if(requestCode==1002 && resultCode==1003)
+            if(data.getStringExtra("result").equals("1")){
+                finish();
+                Intent intent = new Intent(this, TitleActivity.class);
+                startActivity(intent);
+            }
+    }
+    public void openLogin(){
+        Intent intent =new Intent(this, LoginActivity.class);
+        startActivityForResult(intent,1002);
+    }
+    @Override
     protected void onResume() {
         super.onResume();
         StatService.onResume(this);
diff --git a/app/src/main/res/layout/activity_login.xml b/app/src/main/res/layout/activity_login.xml
new file mode 100644
index 0000000..1479052
--- /dev/null
+++ b/app/src/main/res/layout/activity_login.xml
@@ -0,0 +1,77 @@
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:gravity="center_horizontal"
+    android:orientation="vertical"
+    android:paddingBottom="@dimen/activity_vertical_margin"
+    android:paddingLeft="@dimen/activity_horizontal_margin"
+    android:paddingRight="@dimen/activity_horizontal_margin"
+    android:paddingTop="@dimen/activity_vertical_margin"
+    tools:context="com.njzjz.chemicaltools.LoginActivity">
+
+    <!-- Login progress -->
+    <ProgressBar
+        android:id="@+id/login_progress"
+        style="?android:attr/progressBarStyleLarge"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="8dp"
+        android:visibility="gone" />
+
+    <ScrollView
+        android:id="@+id/login_form"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <LinearLayout
+            android:id="@+id/email_login_form"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="vertical">
+
+            <android.support.design.widget.TextInputLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content">
+
+                <AutoCompleteTextView
+                    android:id="@+id/email"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:hint="@string/prompt_email"
+                    android:inputType="textEmailAddress"
+                    android:maxLines="1"
+                    android:singleLine="true" />
+
+            </android.support.design.widget.TextInputLayout>
+
+            <android.support.design.widget.TextInputLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content">
+
+                <EditText
+                    android:id="@+id/password"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:hint="@string/prompt_password"
+                    android:imeActionId="@+id/login"
+                    android:imeActionLabel="@string/action_sign_in_short"
+                    android:imeOptions="actionUnspecified"
+                    android:inputType="textPassword"
+                    android:maxLines="1"
+                    android:singleLine="true" />
+
+            </android.support.design.widget.TextInputLayout>
+
+            <Button
+                android:id="@+id/email_sign_in_button"
+                style="?android:textAppearanceSmall"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="16dp"
+                android:text="@string/action_sign_in"
+                android:textStyle="bold" />
+
+        </LinearLayout>
+    </ScrollView>
+</LinearLayout>
diff --git a/app/src/main/res/values-en/strings.xml b/app/src/main/res/values-en/strings.xml
index 3c163b9..0f6980a 100644
--- a/app/src/main/res/values-en/strings.xml
+++ b/app/src/main/res/values-en/strings.xml
@@ -70,4 +70,16 @@
     <string name="basename">Base name</string>
     <string name="elementWikipedia">Visit Wikipedia</string>
     <string name="juhao">.</string>
+    <string name="action_sign_in_short">Sign in</string>
+    <string name="action_sign_in">Sign in or register</string>
+    <string name="button_user">User centre</string>
+    <string name="button_login">Login</string>
+    <string name="error_field_required">This field is required</string>
+    <string name="error_incorrect_password">This password is incorrect</string>
+    <string name="error_invalid_email">This email address is invalid</string>
+    <string name="error_invalid_password">This password is too short</string>
+    <string name="title_activity_login">Sign in</string>
+    <string name="prompt_email">Email</string>
+    <string name="prompt_password">Password (optional)</string>
+    <string name="action_sign_out">Sign Out</string>
 </resources>
diff --git a/app/src/main/res/values-zh/strings.xml b/app/src/main/res/values-zh/strings.xml
index 0f2e986..b601297 100644
--- a/app/src/main/res/values-zh/strings.xml
+++ b/app/src/main/res/values-zh/strings.xml
@@ -71,4 +71,16 @@
     <string name="basename">请输入碱的名称</string>
     <string name="elementWikipedia">访问维基百科</string>
     <string name="juhao">。</string>
+    <string name="action_sign_in_short">登陆</string>
+    <string name="action_sign_in">登陆/注册</string>
+    <string name="button_user">用户中心</string>
+    <string name="button_login">登陆</string>
+    <string name="error_field_required">这是必填项</string>
+    <string name="error_invalid_password">密码太短</string>
+    <string name="error_incorrect_password">密码错误</string>
+    <string name="error_invalid_email">邮箱非法</string>
+    <string name="title_activity_login">登陆</string>
+    <string name="prompt_email">邮箱</string>
+    <string name="prompt_password">密码</string>
+    <string name="action_sign_out">注销</string>
 </resources>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 5a2fc6c..d2e6333 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -79,4 +79,21 @@
     <string name="setting_mode_9">Answer Chinese names according to IUPAC names</string>
     <string name="setting_mode_10">Answer symbols for elements according to IUPAC names</string>
     <string name="setting_mode_11">Answer atomic numbers according to IUPAC names</string>
+    <string name="title_activity_login">Sign in</string>
+
+    <!-- Strings related to login -->
+    <string name="button_login">Login</string>
+    <string name="button_user">User center</string>
+    <string name="prompt_email">Email</string>
+    <string name="prompt_password">Password (optional)</string>
+    <string name="action_sign_in">Sign in or register</string>
+    <string name="action_sign_in_short">Sign in</string>
+    <string name="action_sign_out">Sign Out</string>
+    <string name="error_invalid_email">This email address is invalid</string>
+    <string name="error_invalid_password">This password is too short</string>
+    <string name="error_incorrect_password">This password is incorrect</string>
+    <string name="error_field_required">This field is required</string>
+    <string name="permission_rationale">"Contacts permissions are needed for providing email
+        completions."
+    </string>
 </resources>
diff --git a/app/src/main/res/xml/settings_general.xml b/app/src/main/res/xml/settings_general.xml
index c98d506..5dc65b4 100644
--- a/app/src/main/res/xml/settings_general.xml
+++ b/app/src/main/res/xml/settings_general.xml
@@ -1,5 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
+    <PreferenceCategory android:title="@string/button_user">
+        <PreferenceScreen android:title="@string/button_login" android:key="login"/>
+    </PreferenceCategory>
     <PreferenceCategory android:title="@string/button_exam">
         <ListPreference android:title="@string/setting_mode"
             android:key="examMode"
diff --git a/build.gradle b/build.gradle
index a3330d4..76b266a 100644
--- a/build.gradle
+++ b/build.gradle
@@ -3,6 +3,9 @@
 buildscript {
     repositories {
         jcenter()
+        maven {
+            url "http://mvn.leancloud.cn/nexus/content/repositories/releases"
+        }
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:2.2.0'
@@ -15,6 +18,10 @@ buildscript {
 allprojects {
     repositories {
         jcenter()
+        maven {
+            url "http://mvn.leancloud.cn/nexus/content/repositories/releases"
+        }
+
     }
 }