Gets a reference to the SheetActivate event
CXlSheetActivateEvent& SheetActivateEvent( );
The function returns a reference to the application's SheetActivate event, which is of type CXlSheetActivateEvent.
The SheetActivate event is raised when a worksheet is activated. All registered observers receive the event via the CXlEventObserver::Update method.
When observers are notified, an argument of type CXlWorksheetEventArgs is passed.
Observers can register for this event at any point in the life of the XLL. Registration can be done explicitly using Register, or automatically by creating an instance of CXlSheetActivateEventStaticObserver.