Assembly: System.Design (in system.design.dll)
A ViewEventHandler delegate method compares the EventType property to the static ViewEvent fields to determine which type of action raised the event. A ViewEvent object is equal to Click to indicate that you clicked a region on the design surface.
The ControlDesigner class supplies a default ViewEventHandler delegate. If the event type is Click, the delegate calls the OnClick method. Classes deriving from the ControlDesigner class override the OnClick method to handle click events on a region at design time. The event arguments indicate which designer region was clicked, if any.