public event RowAllowEventHandler GroupRowExpanding
Public Event GroupRowExpanding As RowAllowEventHandler
The GroupRowExpanding event handler receives an argument of the DevExpress.UI.Xaml.Grid.RowAllowEventArgs type.
The GroupRowExpanding event is raised before a group row is expanded by an end-user or in code, allowing you to cancel this action. The group row is identified by its handle via the RowHandle property. To prevent the group row from being expanded, set the event parameter's Allow parameter to false.