protected override void OnNavigatedFrom(NavigationEventArgs e)
 {
     horizontalScrollableWindow?.Dispose();
     horizontalScrollableWindow = null;
     verticalScrollableWindow?.Dispose();
     verticalScrollableWindow = null;
     lineDisplay?.Dispose();
     lineDisplay = null;
 }
 protected override void OnNavigatedFrom(NavigationEventArgs e)
 {
     lineDisplay?.Dispose();
     lineDisplay = null;
 }