private void OnRowDeleted (object sender, DataRowChangeEventArgs args)
{
/* ItemDeleted */
int newIndex, oldCount;
oldCount = Count;
newIndex = IndexOf (args.Row);
UpdateIndex (true);
/* Fire ListChanged only when the RowFilter is affected */
if (oldCount != Count)
OnListChanged (new ListChangedEventArgs (ListChangedType.ItemDeleted, newIndex, -1));
}