The event handler receives an argument of type DevExpress.XtraEditors.Events.PopupMenuShowingEventArgs containing data related to this event.
The PopupMenuShowing event fires when the context menu is about to be displayed. Handle this event to customize the context menu or to prevent it from being displayed. The editor's PopupMenuShowing event is equivalent to the RepositoryItemPictureEdit.PopupMenuShowing event available via the Properties object. See RepositoryItemPictureEdit.PopupMenuShowing for details.