Updates the expiration date and time of an item in the session data store.
Assembly: System.Web (in System.Web.dll)
the EnableSessionState attribute is true, or
If an ASP.NET page is requested and the EnableSessionState attribute is set to false, the method is still called to update the expiration date and time of the data in the session data store.
For an example of a session-state store provider implementation, see Implementing a Session-State Store Provider.