diff --git a/CHANGELOG.md b/CHANGELOG.md
index 87b71a6..3b6a5ba 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+### 2.5.0
+- Add more reliable `WinApi.GetScaleFactor(Hwnd hwnd)`
+
 ### 2.4.0
 - `FreSharp.dispose()` is now static funcion 
 
diff --git a/framework_src/FreSharp/Properties/AssemblyInfo.cs b/framework_src/FreSharp/Properties/AssemblyInfo.cs
index 56c5f49..8888ca5 100644
--- a/framework_src/FreSharp/Properties/AssemblyInfo.cs
+++ b/framework_src/FreSharp/Properties/AssemblyInfo.cs
@@ -32,7 +32,7 @@
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("2.4.0.0")]
-[assembly: AssemblyFileVersion("2.4.0.0")]
+[assembly: AssemblyVersion("2.5.0.0")]
+[assembly: AssemblyFileVersion("2.5.0.0")]
 [assembly: NeutralResourcesLanguage("en")]
 
diff --git a/framework_src/FreSharp/Utils/WinAPI.cs b/framework_src/FreSharp/Utils/WinAPI.cs
index f5ed1bd..26a765a 100644
--- a/framework_src/FreSharp/Utils/WinAPI.cs
+++ b/framework_src/FreSharp/Utils/WinAPI.cs
@@ -2,6 +2,7 @@
 using System.Drawing;
 using System.Runtime.InteropServices;
 using Hwnd = System.IntPtr;
+using Hmonitor = System.IntPtr;
 // ReSharper disable MemberCanBePrivate.Global
 // ReSharper disable UnusedMember.Global
 // ReSharper disable FieldCanBeMadeReadOnly.Global
@@ -14,9 +15,8 @@ namespace TuaRua.FreSharp.Utils {
     /// </summary>
     public static class WinApi {
         private const string User32 = "user32";
-
-        //private const string Kernel32 = "kernel32";
         private const string Gdi32 = "gdi32";
+        private const string ShCore = "shcore";
 
         public static double GetScaleFactor() {
             var g = Graphics.FromHwnd(Hwnd.Zero);
@@ -37,6 +37,19 @@ public static double GetScaleFactor() {
             return 1.0;
         }
 
+        /// <summary>
+        /// Gets the scale factor of the monitor.
+        /// </summary>
+        /// <param name="hwnd">A handle to the window of interest.</param>
+        /// <returns></returns>
+        public static double GetScaleFactor(Hwnd hwnd) {
+            GetScaleFactorForMonitor(
+                MonitorFromWindow(hwnd, MonitorFlags.MONITOR_DEFAULTTONEAREST),
+                out int dsf);
+            if (dsf < 100) dsf = 100;
+            return Convert.ToDouble(dsf) / 100.0;
+        }
+
         /// <summary>
         /// 
         /// </summary>
@@ -78,7 +91,6 @@ public static extern bool SetWindowPos(Hwnd hwnd, Hwnd hWndInsertAfter, int x, i
         [DllImport(User32, ExactSpelling = true)]
         public static extern bool RegisterTouchWindow(Hwnd hwnd, TouchWindowFlags flags);
 
-
         /// <summary>
         /// 
         /// </summary>
@@ -102,13 +114,44 @@ public static extern bool SetLayeredWindowAttributes(Hwnd hwnd, uint crKey, byte
 
         [DllImport(Gdi32, ExactSpelling = true)]
         public static extern int GetDeviceCaps(Hwnd hdc, int nIndex);
-    }
 
+        /// <summary>
+        /// Gets the scale factor of a specific monitor.
+        /// </summary>
+        /// <param name="hMon">The monitor's handle.</param>
+        /// <param name="pScale">When this function returns successfully, this value points to one of the
+        /// DEVICE_SCALE_FACTOR values that specify the scale factor of the specified monitor.
+        /// If the function call fails, this value points to a valid scale factor so that apps can opt to
+        /// continue on with incorrectly sized resources.</param>
+        /// <returns>If this function succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.</returns>
+        [DllImport(ShCore)]
+        public static extern Hwnd GetScaleFactorForMonitor([In]Hmonitor hMon, [Out]out int pScale);
+
+        /// <summary>
+        /// The MonitorFromWindow function retrieves a handle to the display monitor that has the largest area of
+        /// intersection with the bounding rectangle of a specified window.
+        /// </summary>
+        /// <param name="hwnd">A handle to the window of interest.</param>
+        /// <param name="dwFlags">Determines the function's return value if the window does not intersect any display monitor.</param>
+        /// <returns>If the window intersects one or more display monitor rectangles, the return value is
+        /// an HMONITOR handle to the display monitor that has the largest area of intersection with the window.
+        /// If the window does not intersect a display monitor, the return value depends on the value of dwFlags.</returns>
+        [DllImport(User32)]
+        public static extern Hmonitor MonitorFromWindow(Hwnd hwnd, MonitorFlags dwFlags);
+    }
     [Flags]
-    public enum WindowLongFlags {
+    public enum WindowLongFlags
+    {
         GWL_EXSTYLE = -20
     }
 
+    [Flags]
+    public enum MonitorFlags {
+        MONITOR_DEFAULTTONULL = 0,
+        MONITOR_DEFAULTTOPRIMARY = 1,
+        MONITOR_DEFAULTTONEAREST = 2
+    }
+
     [Flags]
     public enum ShowWindowCommands {
         SW_FORCEMINIMIZE = 11,
diff --git a/framework_src/FreSharpCore/FreSharpCore.rc b/framework_src/FreSharpCore/FreSharpCore.rc
index e0d1eaa..bcf1422 100644
Binary files a/framework_src/FreSharpCore/FreSharpCore.rc and b/framework_src/FreSharpCore/FreSharpCore.rc differ
diff --git a/framework_src/example/native_extension/ane/FreSharpExampleANE.ane b/framework_src/example/native_extension/ane/FreSharpExampleANE.ane
index 859cb75..b98f479 100644
Binary files a/framework_src/example/native_extension/ane/FreSharpExampleANE.ane and b/framework_src/example/native_extension/ane/FreSharpExampleANE.ane differ
diff --git a/framework_src/example/native_extension/ane/extension.xml b/framework_src/example/native_extension/ane/extension.xml
index 258c6e0..80a7d34 100644
--- a/framework_src/example/native_extension/ane/extension.xml
+++ b/framework_src/example/native_extension/ane/extension.xml
@@ -3,7 +3,7 @@
     <id>com.tuarua.FreSharpExampleANE</id>
     <name>FreSharp Example ANE</name>
     <copyright>his work is licensed under MIT License, Copyright (c) 2017 Tua Rua Ltd.</copyright>
-    <versionNumber>2.4.0</versionNumber>
+    <versionNumber>2.5.0</versionNumber>
 	<platforms>
         <platform name="Windows-x86">
             <applicationDeployment>
diff --git a/framework_src/fresharp_native_extension/ane/FreSharp.ane b/framework_src/fresharp_native_extension/ane/FreSharp.ane
index 739b9af..c2ea756 100644
Binary files a/framework_src/fresharp_native_extension/ane/FreSharp.ane and b/framework_src/fresharp_native_extension/ane/FreSharp.ane differ
diff --git a/framework_src/fresharp_native_extension/ane/extension.xml b/framework_src/fresharp_native_extension/ane/extension.xml
index 41915a0..953f81c 100644
--- a/framework_src/fresharp_native_extension/ane/extension.xml
+++ b/framework_src/fresharp_native_extension/ane/extension.xml
@@ -3,7 +3,7 @@
 	<id>com.tuarua.FreSharp</id>
 	<name>FreSharp</name>
 	<copyright>This work is licensed under Apache License, Copyright (c) 2017 Tua Rua Ltd.</copyright>
-	<versionNumber>2.4.0</versionNumber>
+	<versionNumber>2.5.0</versionNumber>
 	<platforms>
 	<platform name="Windows-x86">
             <applicationDeployment>
diff --git a/starter_project/native_library/win/HelloWorldANE/HelloWorldANE/HelloWorldANE.vcxproj b/starter_project/native_library/win/HelloWorldANE/HelloWorldANE/HelloWorldANE.vcxproj
index dfdae40..16f02a2 100644
--- a/starter_project/native_library/win/HelloWorldANE/HelloWorldANE/HelloWorldANE.vcxproj
+++ b/starter_project/native_library/win/HelloWorldANE/HelloWorldANE/HelloWorldANE.vcxproj
@@ -181,7 +181,7 @@
     </PostBuildEvent>
   </ItemDefinitionGroup>
   <ItemGroup>
-    <ClInclude Include="..\..\..\..\..\..\..\sdks\AIR\AIRSDK_29\include\FlashRuntimeExtensions.h" />
+    <ClInclude Include="D:\dev\sdks\AIR\AIRSDK_32\include\FlashRuntimeExtensions.h" />
     <ClInclude Include="FreNamespace.h" />
     <ClInclude Include="FreSharpBridge.h" />
     <ClInclude Include="FreSharpMacros.h" />
@@ -194,7 +194,7 @@
   </ItemGroup>
   <ItemGroup>
     <Reference Include="FreSharp">
-      <HintPath>..\packages\TuaRua.FreSharp.2.4.0\FreSharp\$(PlatformTarget)\FreSharp.dll</HintPath>
+      <HintPath>..\packages\TuaRua.FreSharp.2.5.0\FreSharp\$(PlatformTarget)\FreSharp.dll</HintPath>
     </Reference>
     <Reference Include="PresentationCore" />
     <Reference Include="PresentationFramework" />
diff --git a/starter_project/native_library/win/HelloWorldANE/HelloWorldANELib/HelloWorldANELib.csproj b/starter_project/native_library/win/HelloWorldANE/HelloWorldANELib/HelloWorldANELib.csproj
index e0688e2..377437c 100644
--- a/starter_project/native_library/win/HelloWorldANE/HelloWorldANELib/HelloWorldANELib.csproj
+++ b/starter_project/native_library/win/HelloWorldANE/HelloWorldANELib/HelloWorldANELib.csproj
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\packages\TuaRua.FreSharp.2.4.0\build\TuaRua.FreSharp.props" Condition="Exists('..\packages\TuaRua.FreSharp.2.4.0\build\TuaRua.FreSharp.props')" />
+  <Import Project="..\packages\TuaRua.FreSharp.2.5.0\build\TuaRua.FreSharp.props" Condition="Exists('..\packages\TuaRua.FreSharp.2.5.0\build\TuaRua.FreSharp.props')" />
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -89,8 +89,8 @@
     <PropertyGroup>
       <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
     </PropertyGroup>
-    <Error Condition="!Exists('..\packages\TuaRua.FreSharp.2.4.0\build\TuaRua.FreSharp.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\TuaRua.FreSharp.2.4.0\build\TuaRua.FreSharp.props'))" />
-    <Error Condition="!Exists('..\packages\TuaRua.FreSharp.2.4.0\build\TuaRua.FreSharp.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\TuaRua.FreSharp.2.4.0\build\TuaRua.FreSharp.targets'))" />
+    <Error Condition="!Exists('..\packages\TuaRua.FreSharp.2.5.0\build\TuaRua.FreSharp.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\TuaRua.FreSharp.2.5.0\build\TuaRua.FreSharp.props'))" />
+    <Error Condition="!Exists('..\packages\TuaRua.FreSharp.2.5.0\build\TuaRua.FreSharp.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\TuaRua.FreSharp.2.5.0\build\TuaRua.FreSharp.targets'))" />
   </Target>
-  <Import Project="..\packages\TuaRua.FreSharp.2.4.0\build\TuaRua.FreSharp.targets" Condition="Exists('..\packages\TuaRua.FreSharp.2.4.0\build\TuaRua.FreSharp.targets')" />
+  <Import Project="..\packages\TuaRua.FreSharp.2.5.0\build\TuaRua.FreSharp.targets" Condition="Exists('..\packages\TuaRua.FreSharp.2.5.0\build\TuaRua.FreSharp.targets')" />
 </Project>
\ No newline at end of file
diff --git a/starter_project/native_library/win/HelloWorldANE/HelloWorldANELib/packages.config b/starter_project/native_library/win/HelloWorldANE/HelloWorldANELib/packages.config
index 8fd1f97..2b7de11 100644
--- a/starter_project/native_library/win/HelloWorldANE/HelloWorldANELib/packages.config
+++ b/starter_project/native_library/win/HelloWorldANE/HelloWorldANELib/packages.config
@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="TuaRua.FreSharp" version="2.4.0" targetFramework="net46" />
+  <package id="TuaRua.FreSharp" version="2.5.0" targetFramework="net46" />
 </packages>
\ No newline at end of file