Merge pull request #525 from dotnet-campus/t/lindexi/Touch-DragMove

加入支持触摸的辅助方法和测试代码

src/Shared/HandyControlDemo_Shared/UserControl/Styles/NativeWindowDemoCtl.xaml

@@ -11,6 +11,7 @@
         <UniformGrid Margin="32" Columns="3" Rows="3" Height="200">
             <Button Command="{Binding OpenWindowCmd}" CommandParameter="{x:Static data:MessageToken.NativeCommonWindow}" Content="{ex:Lang Key={x:Static langs:LangKeys.OpenNativeCommonWindow}}"/>
             <Button Command="{Binding OpenWindowCmd}" CommandParameter="{x:Static data:MessageToken.NavigationWindow}" Content="{ex:Lang Key={x:Static langs:LangKeys.OpenNavigationWindow}}"/>
+            <Button Command="{Binding OpenWindowCmd}" CommandParameter="{x:Static data:MessageToken.TouchDragMoveWindow}" Content="{ex:Lang Key={x:Static langs:LangKeys.OpenTouchDragMoveWindow}}"/>
         </UniformGrid>
     </hc:TransitioningContentControl>
 </UserControl>