/// <summary>
 /// Invoked when this page is about to be displayed in a Frame.
 /// </summary>
 /// <param name="e">Event data that describes how this page was reached.  The Parameter
 /// property is typically used to configure the page.</param>
 protected override void OnNavigatedTo(NavigationEventArgs e)
 {
     UpdateDrawingPanelLayout();
     DrawingPanel.StartProcessingInput();
 }