WeakEventManager.Purge Method (Object, Object, Boolean)


Removes inactive listener entries from the data list for the provided source. Returns true if some entries were actually removed from the list.

Namespace:   System.Windows
Assembly:  WindowsBase (in WindowsBase.dll)

Protected Overridable Function Purge (
	source As Object,
	data As Object,
	purgeAll As Boolean
) As Boolean


Type: System.Object

The source for events being listened to.

Type: System.Object

The data to check. This object is expected to be a WeakEventManager.ListenerList implementation.

Type: System.Boolean

true to stop listening to source, and completely remove all entries from data.

Return Value

Type: System.Boolean

true if some entries were actually removed; otherwise, false.

The Purge method has a default implementation that will remove all entries when data is a WeakEventManager.ListenerList.

Notes to Implementers:

If the underlying type for the Item is something other than WeakEventManager.ListenerList, or contains data beyond a WeakEventManager.ListenerList, you must override the Purge method. The override should provide purge behavior for the alternate type items list. Generally, the override should provide behavior without calling the base implementation. If a specific WeakEventManager.ListenerList still needs clearing, call Purge.

.NET Framework
Available since 3.0
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