update to androidX

app/build.gradle

@@ -1,15 +1,16 @@
 apply plugin: 'com.android.application'
-
 apply plugin: 'kotlin-android'
-
 apply plugin: 'kotlin-android-extensions'
+apply plugin: 'kotlin-kapt'
 
 android {
-    compileSdkVersion 27
+    compileSdkVersion 30
+    buildToolsVersion "30.0.2"
+
     defaultConfig {
         applicationId "com.reesehu.hcountdowntimer"
-        minSdkVersion 14
-        targetSdkVersion 27
+        minSdkVersion 21
+        targetSdkVersion 30
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -20,15 +21,39 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+    lintOptions {
+        disable 'InvalidPackage'
+        disable "ResourceType"
+        abortOnError false
+    }
+    compileOptions {
+        targetCompatibility JavaVersion.VERSION_1_8
+        sourceCompatibility JavaVersion.VERSION_1_8
+    }
+    kotlinOptions {
+        jvmTarget = '1.8'
+        freeCompilerArgs += ["-Xopt-in=kotlin.RequiresOptIn"]
+    }
 }
 
 dependencies {
-    implementation fileTree(dir: 'libs', include: ['*.jar'])
-    implementation "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
-    implementation 'com.android.support:appcompat-v7:27.1.1'
-    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
-    implementation 'com.android.support:design:27.1.1'
-    testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'com.android.support.test:runner:1.0.1'
-    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
+    implementation fileTree(dir: "libs", include: ["*.jar"])
+
+    implementation 'androidx.navigation:navigation-fragment-ktx:2.3.2'
+    implementation 'androidx.navigation:navigation-ui-ktx:2.3.2'
+    implementation 'androidx.navigation:navigation-fragment-ktx:2.3.2'
+    implementation 'androidx.navigation:navigation-ui-ktx:2.3.2'
+    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
+    implementation 'androidx.lifecycle:lifecycle-common-java8:2.2.0'
+    //noinspection LifecycleAnnotationProcessorWithJava8
+    kapt 'androidx.lifecycle:lifecycle-compiler:2.2.0'
+    implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.2.0'
+    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
+    implementation 'androidx.core:core-ktx:1.3.2'
+    implementation 'androidx.appcompat:appcompat:1.2.0'
+    implementation 'com.google.android.material:material:1.2.1'
+    implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
+    testImplementation 'junit:junit:4.13.1'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.2'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
 }

app/src/main/java/com/reesehu/hcountdowntimer/MainActivity.kt

@@ -1,10 +1,10 @@
 package com.reesehu.hcountdowntimer
 
 import android.os.Bundle
-import android.support.design.widget.Snackbar
-import android.support.v7.app.AppCompatActivity
 import android.view.Menu
 import android.view.MenuItem
+import androidx.appcompat.app.AppCompatActivity
+import com.google.android.material.snackbar.Snackbar
 import kotlinx.android.synthetic.main.activity_main.*
 import kotlinx.android.synthetic.main.content_main.*
 
@@ -24,7 +24,7 @@ class MainActivity : AppCompatActivity() {
 
         fab.setOnClickListener { view ->
             Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
-                    .setAction("Action", null).show()
+                .setAction("Action", null).show()
         }
         bit_flip.flip(0) // 设置默认为0
         btn_test.setOnClickListener {