public class RowAllowEventArgs : RowEventArgs
Public Class RowAllowEventArgs Inherits RowEventArgs
To cancel the action, set the event parameter's RowAllowEventArgs.Allow property to false. The processed row is returned by the RowEventArgs.Row property. Its handle is returned by the RowEventArgs.RowHandle property.
To learn more, see Expanding and Collapsing Group Rows.