¿Cómo eliminar todos los controladores de eventos Click?

Question

Duplicar posible: How would that be possible to remove all event handlers of the Click event of a Button?

que desea eliminar todos los controladores de eventos Click de un botón. Encontré este método en la pregunta de desbordamiento de pila How to remove all event handlers from a control.

private void RemoveClickEvent(Button b) 
{ 
    FieldInfo f1 = typeof(Control).GetField("EventClick", 
              BindingFlags.Static | 
              BindingFlags.NonPublic); 
    object obj = f1.GetValue(b); 
    PropertyInfo pi = b.GetType().GetProperty("Events", 
               BindingFlags.NonPublic | 
               BindingFlags.Instance); 
    EventHandlerList list = (EventHandlerList)pi.GetValue(b, null); 
    list.RemoveHandler(obj, list[obj]); 
} 

Pero esta línea siempre devuelve nulo:

typeof(Control).GetField("EventClick", BindingFlags.Static | BindingFlags.NonPublic); 

Y este método fue escrito en 2006.

¿Hay alguna versión más reciente de este método?

Nota: Estoy trabajando con WPF y .NET 4.0.

Answer 1

A continuación es un método de utilidad muy útil para la recuperación de todos los controladores de eventos suscritos para cualquier evento enrutado:

/// <summary> 
/// Gets the list of routed event handlers subscribed to the specified routed event. 
/// </summary> 
/// <param name="element">The UI element on which the event is defined.</param> 
/// <param name="routedEvent">The routed event for which to retrieve the event handlers.</param> 
/// <returns>The list of subscribed routed event handlers.</returns> 
public static RoutedEventHandlerInfo[] GetRoutedEventHandlers(UIElement element, RoutedEvent routedEvent) 
{ 
    // Get the EventHandlersStore instance which holds event handlers for the specified element. 
    // The EventHandlersStore class is declared as internal. 
    var eventHandlersStoreProperty = typeof(UIElement).GetProperty(
     "EventHandlersStore", BindingFlags.Instance | BindingFlags.NonPublic); 
    object eventHandlersStore = eventHandlersStoreProperty.GetValue(element, null); 

    // Invoke the GetRoutedEventHandlers method on the EventHandlersStore instance 
    // for getting an array of the subscribed event handlers. 
    var getRoutedEventHandlers = eventHandlersStore.GetType().GetMethod(
     "GetRoutedEventHandlers", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic); 
    var routedEventHandlers = (RoutedEventHandlerInfo[])getRoutedEventHandlers.Invoke(
     eventHandlersStore, new object[] { routedEvent }); 

    return routedEventHandlers; 
} 

Utilizando lo anterior, la implementación de su método se vuelve bastante simple:

private void RemoveClickEvent(Button b) 
{ 
    var routedEventHandlers = GetRoutedEventHandlers(b, ButtonBase.ClickEvent); 
    foreach (var routedEventHandler in routedEventHandlers) 
     b.Click -= (RoutedEventHandler)routedEventHandler.Handler; 
}