public void ShowMessageOverlay(string title, string message, string option, MessageOverlayTypes type = MessageOverlayTypes.Ok, MessageOverlay.DoneCallbackMethod doneCallback = null)
 {
     ShowMessageOverlayInternal(title, message, option, type, doneCallback);
 }
 private void ShowMessageOverlayInternal(string title, string message, string option, MessageOverlayTypes type, MessageOverlay.DoneCallbackMethod doneCallback)
 {
     if (Dispatcher.CheckAccess())
     {
         messageOverlay.Setup(title, message, option, type, doneCallback);
         messageOverlay.Visibility = Visibility.Visible;
     }
     else
     {
         Dispatcher.InvokeAsync(delegate()
         {
             messageOverlay.Setup(title, message, option, type, doneCallback);
             messageOverlay.Visibility = Visibility.Visible;
         });
     }
 }