Play an animation when the content of the badge is changed, and add the related demo.

HandyControlDemo/HandyControlDemo.csproj

@@ -364,6 +364,7 @@
     <Compile Include="ViewModel\Basic\ChatBoxViewModel.cs" />
     <Compile Include="ViewModel\Basic\InteractiveDialogViewModel.cs" />
     <Compile Include="ViewModel\Common\ComboBoxDemoViewModel.cs" />
+    <Compile Include="ViewModel\Controls\BadgeDemoCtlViewModel.cs" />
     <Compile Include="ViewModel\Controls\CoverViewModel.cs" />
     <Compile Include="ViewModel\Controls\DialogDemoViewModel.cs" />
     <Compile Include="ViewModel\Controls\NotifyIconDemoViewModel.cs" />