The GridTabControl has the GridTabControlDesigner designer class associated with it. The main reason for introducing this class is to enable the tab switching functionality and responsiveness to the mouse input at design time. Default designer handles all the mouse input, so the control does not have a chance to react to mouse events.

The GridTabControlDesigner, derived from ScrollableControlDesigner, translates the Windows WM_MOUSEMOVE and WM_LBUTTONDOWN messages into calls of special design time support functions DesignerMouseMove and DesignerMouseDown of the designed GridTabControl control associated with the designer.

Normally an application developer does not need to do anything specific regarding the designer class. This class is used by the Visual Studio.If youderive your own class from the GridTabControl and want to modify the design time behavior, you might need to derive a new designer class and associate it with the control class.