Represents a method that will handle the XPBaseCollection.CollectionChanged event.
The event sender.
An XPCollectionChangedEventArgs object that contains event data.
When you create an XPCollectionChangedEventHandler delegate, you identify the method that will handle the corresponding event. To associate an event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information on event handler delegates, see Events and Delegates in MSDN.