ObjectCollectionBase.OnCollectionChanging Method

[This is preliminary documentation and subject to change.]

Called when the collection is about to be changed.

[Visual Basic]
Protected Sub OnCollectionChanging( _
   ByVal changeType As CollectionChangeType, _
   ByVal itemIndex As Integer, _
   ByVal item As Object _
)

[C#]
protected void OnCollectionChanging(
   CollectionChangeType changeType,
   int itemIndex,
   object item
);

Remarks

The implementation creates and caches a new CollectionChangeEventArgs instance and dispatches the event by means of calling the PropagateChangingEvent method. The corresponding 'changed' event should be raised by calling the OnCollectionChanged method after the collection's value has been changed. In other word, calls to OnCollectionChanging and OnCollectionChanged method should always be balanced.

The implementation calls the OnCollectionChanging method in the OnInsert, OnRemove and OnClear methods, and the OnCollectionChanged in the corresponding OnInsertComplete, OnRemoveComplete and OnClearComplete methods

ObjectCollectionBase.OnCollectionChanging Method

Remarks

See Also