The default implementation of this function calls the OnUpdate member function with no hint information (that is, using the default values of 0 for the lHint parameter and NULL for the pHint parameter). Override this function to perform any one-time initialization that requires information about the document. For example, if your application has fixed-sized documents, you can use this function to initialize a view's scrolling limits based on the document size. If your application supports variable-sized documents, use OnUpdate to update the scrolling limits every time the document changes.