ASP.NET in a Nutshell

Name

SessionID

Synopsis

String = Session.
                     SessionID

Returns a String containing the unique identifier for the current session.

Parameters

String

A String variable that will receive the session ID property value.

Example

See the example for the IsReadOnly property.

Notes

The SessionID property value is generated the first time that a page for which session state has not been disabled is requested. As noted earlier, the actual session is not created unless either an event handler is provided in global.asax for the Session.Start event or a value is stored in the Session collection. The SessionID is stored on the client in a nonpersistent cookie, or if cookieless sessions are enabled, is passed as part of each URL request.

Note that if the client’s browser is closed, the client will be unable to access their session (since the nonpersistent cookie will be destroyed when the browser is closed), but the session will continue to exist on the server until the configured timeout period has elapsed. If you want to explicitly expire a session, you can check the IsClientConnected property of the HttpResponse class, which returns a Boolean indicating whether the client has disconnected. If it returns False, you can then call Session.Abandon to expire the session.

While the SessionID value, which is a 120-bit ASCII string in ASP.NET, is unique to a given IIS application instance, it is not guaranteed to be universally unique and therefore should not be used for database identity values or for other ...