How to: Control Drag-and-drop of Column Headers
The example shows how to prevent moving the "ContactName" column to the Customization Form.
To control drag-and-drop of grid columns, we handle the GridView.DragObjectOver event. The DragObjectOverEventArgs.DropInfo event's parameter contains information on the current position where drag-and-drop will occur if the end-user drops the drag object. The Index property of the DragObjectOverEventArgs.DropInfo would be -1 when dragging over the Customization Form.