protected override void LoadPreviewProvider()
 {
     Controller.Dispatcher.Invoke((Action)delegate
     {
         preview = new LiveWindowPreviewProvider(presentationHandle);
     });
 }
 protected override void LoadPreviewProvider()
 {
     Controller.Dispatcher.Invoke((Action)delegate
     {
         preview = new LiveWindowPreviewProvider(new IntPtr(this.presentation.SlideShowWindow.HWND));
     });
 }