Toggles form design mode on or off.
Assembly: Microsoft.Office.Interop.Excel (in Microsoft.Office.Interop.Excel.dll)
When Excel is in form design mode, the Control Toolbox toolbar is displayed. You can use this toolbar to insert ActiveX controls such as command buttons, scroll bars, and option buttons. In form design mode, event procedures don't run, and when you click an embedded control, the control's sizing handles appear.