Fires before a tab item is inserted, and allows you to prevent this action.
public event TabControlTabInsertingEventHandler TabInserting
Public Event TabInserting As TabControlTabInsertingEventHandler
The TabInserting event's data class is DevExpress.Xpf.Core.TabControlTabInsertingEventArgs.
To prevent a tab item from being inserted during a drag and drop action, set the event's Cancel parameter to true. After an item has been inserted/dropped, the DXTabControl.TabInserted event fires.