WeakEventManager.Item Property (Object)
Gets or sets the data being stored for the specified source.
Assembly: WindowsBase (in WindowsBase.dll)
Derived classes can choose what data and type to store in this indexer. Typically this is implemented as a WeakEventManager.ListenerList, which is a list of weak references to listeners. You would only have to change this type if the WeakEventManager.ListenerList type cannot contain your required information. If so, you will have to override the Purge method so that all cleanup of the underlying type is performed correctly.
Available since 3.0