Assembly: System.Web (in system.web.dll)
The OnPreRender method determines whether the user is logged in by examining the IsAuthenticated property of the Page object's Request property. If the user is logged in, the LogoutText or LogoutImageUrl property is used to render the control. If the user is not logged in, the LoginText or LoginImageUrl property is used to render the control.
For more information about handling events, see Events and Delegates.
The OnPreRender 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 OnPreRender in a derived class, be sure to call the base class's OnPreRender method so that registered delegates receive the event.