Raises the SignInCompleted event. Script: http://www.wlmessenger.net/api/3.7/loader.js
Classes that inherit from this class can override this method to perform additional tasks when the SignInCompleted event occurs.
The OnSignInCompleted method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.
Notes to Inheritors When overriding OnSignInCompleted in a derived class, be sure to call the base class's OnSignInCompleted method so that registered delegates receive the event.