public event DecoratorEventHandler DecoratorShown
        {
            add { AddHandler(DecoratorShownEvent, value); }
            remove { RemoveHandler(DecoratorShownEvent, value); }
        }

public static readonly RoutedEvent DecoratorShownEvent =
  EventManager.RegisterRoutedEvent("DecoratorShown", RoutingStrategy.Bubble, typeof(DecoratorEventHandler), typeof(DecoratorControl));