Occurs when a group row is about to be expanded, allowing cancellation of the action.
public event RowAllowEventHandler GroupRowExpanding
Public Event GroupRowExpanding As RowAllowEventHandler
The event handler receives an argument of the DevExpress.UI.Xaml.Grid.RowAllowEventHandler 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.
The GridControl.ExpandAllGroups method allows you to expand all group rows. In this instance, the GroupRowExpanding event is raised only once. The event parameter's RowHandle property returns an invalid row handle (DataControlBase.InvalidRowHandle).
After the group row has been expanded, the GridControl.GroupRowExpanded event is raised.