How to remove all Click event handlers?
The below is a helpful utility method for retrieving all subscribed event handlers for any routed event:
/// <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;
}
Using the above, the implementation of your method becomes quite simple:
private void RemoveClickEvent(Button b)
{
var routedEventHandlers = GetRoutedEventHandlers(b, ButtonBase.ClickEvent);
foreach (var routedEventHandler in routedEventHandlers)
b.Click -= (RoutedEventHandler)routedEventHandler.Handler;
}
Hasanuzzaman
A full stack software engineer with 7 years of experience in building large-scale applications. Pivotal contributions to the architecture and development life cycle of company projects. I am eager to use my technical skills and vast experiences in building .NET base application at your company.
Updated on June 05, 2022Comments
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Hasanuzzaman almost 2 years
Possible Duplicate: How would that be possible to remove all event handlers of the Click event of a Button?
I want to remove all click event handlers from a button. I found this method in Stack Overflow question 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]); }
But this line always returns null:
typeof(Control).GetField("EventClick", BindingFlags.Static | BindingFlags.NonPublic);
And this method was written in 2006.
Is there any latest version of this method?