An event which is raised when a workbook is opened.
class CXlWorkbookOpenEvent : public CXlEvent
The event occurs when a workbook is opened.
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 CXlWorkbookOpenEventStaticObserver.
When observers are notified, an argument of type CXlWorkbookEventArgs is passed.