diff --git a/Implab.Fx.Test/Implab.Fx.Test.csproj b/Implab.Fx.Test/Implab.Fx.Test.csproj
--- a/Implab.Fx.Test/Implab.Fx.Test.csproj
+++ b/Implab.Fx.Test/Implab.Fx.Test.csproj
@@ -10,9 +10,10 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Implab.Fx.Test</RootNamespace>
     <AssemblyName>Implab.Fx.Test</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <ProjectTypeGuids>{3AC096D0-A1C2-E12C-1390-A8335801FDAB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -22,6 +23,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -30,6 +32,7 @@
     <DefineConstants>TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug 4.5|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -39,6 +42,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release 4.5|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -47,6 +51,7 @@
     <DefineConstants>TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="Microsoft.VisualStudio.QualityTools.UnitTestFramework, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL" />
diff --git a/Implab.Fx.Test/OverlayTest.cs b/Implab.Fx.Test/OverlayTest.cs
--- a/Implab.Fx.Test/OverlayTest.cs
+++ b/Implab.Fx.Test/OverlayTest.cs
@@ -27,7 +27,7 @@ namespace Implab.Fx.Test
             mainForm.ButtonEvent += (sender, args) =>
             {
                 var overlay = new OverlayForm();
-                mainForm.OverlayFadeIn(overlay).Then(
+                mainForm.OverlayFadeIn(overlay).On(
                     o => o.ButtonEvent += (s2, args2) => o.CloseFadeOut()
                 );
             };
diff --git a/Implab.Fx/Implab.Fx.csproj b/Implab.Fx/Implab.Fx.csproj
--- a/Implab.Fx/Implab.Fx.csproj
+++ b/Implab.Fx/Implab.Fx.csproj
@@ -10,9 +10,10 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Implab.Fx</RootNamespace>
     <AssemblyName>Implab.Fx</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <ReleaseVersion>0.2</ReleaseVersion>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -22,6 +23,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -30,6 +32,7 @@
     <DefineConstants>TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug 4.5|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -39,6 +42,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release 4.5|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -47,6 +51,7 @@
     <DefineConstants>TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="System" />
@@ -68,7 +73,7 @@
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Implab\Implab.csproj">
-      <Project>{F550F1F8-8746-4AD0-9614-855F4C4B7F05}</Project>
+      <Project>{f550f1f8-8746-4ad0-9614-855f4c4b7f05}</Project>
       <Name>Implab</Name>
     </ProjectReference>
   </ItemGroup>
diff --git a/Implab.Test/Implab.Test.csproj b/Implab.Test/Implab.Test.csproj
--- a/Implab.Test/Implab.Test.csproj
+++ b/Implab.Test/Implab.Test.csproj
@@ -10,9 +10,10 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Implab.Test</RootNamespace>
     <AssemblyName>Implab.Test</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <ProjectTypeGuids>{3AC096D0-A1C2-E12C-1390-A8335801FDAB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -22,6 +23,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -30,6 +32,7 @@
     <DefineConstants>TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug 4.5|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -39,6 +42,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release 4.5|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -47,6 +51,7 @@
     <DefineConstants>TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="Microsoft.VisualStudio.QualityTools.UnitTestFramework, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL" />