WeakEventManager.ListenerList.Add(IWeakEventListener) Method


 void Add(System::Windows::IWeakEventListener ^ listener);
public void Add (System.Windows.IWeakEventListener listener);
member this.Add : System.Windows.IWeakEventListener -> unit
Public Sub Add (listener As IWeakEventListener)



The listener element to add to the WeakEventManager.ListenerList.


The object provided as listener should be a DependencyObject that implements the IWeakEventListener interface and therefore has a working ReceiveWeakEvent implementation.

You should always call PrepareForWriting before changing the list contents. Otherwise, the list may be in process of delivering events and therefore the original is locked. Calling PrepareForWriting changes the input list to be a clone so that your Add call can still work on the clone. If PrepareForWriting returns true, you might need to update any private references to the list that you maintain in other areas of your code.

Applies to

See also