I am trying to toggle a small StackPanel on top of a large StackPanel: when the small StackPanel is toggled and show visible, the large StackPanel on the back is grey out with a opacity color. Does anyone know how can I grey out a whole StackPanel?
You could try to disable the StackPanel
(stackPanel.IsEnabled = false;
), then all children of that StackPanel
will also be disabled which normally takes the apprearance of greyed out controls.