会话超时后两次调用Session_End事件

Question

出于安全目的，我在用户登录后重新生成了会话。但是Session_End事件调用了两次，一次是旧会话，一次是新会话。如何限制旧事件调用的Session_End事件？

我使用以下代码来生成新会话。

// code to generate new session
SessionIDManager sessionManager = new SessionIDManager();
            string oldSessionId = sessionManager.GetSessionID( Context );
            string newSessionId = sessionManager.CreateSessionID( Context );
            bool isCookieAdded = false, isRedirected = false;
            sessionManager.SaveSessionID( Context, newSessionId, out isRedirected, out isCookieAdded );
            HttpApplication application = HttpContext.Current.ApplicationInstance;
            SessionStateModule sessionStateModule = (SessionStateModule) application.Modules.Get( "Session" );
            FieldInfo[] fields = sessionStateModule.GetType().GetFields( BindingFlags.NonPublic | BindingFlags.Instance );
            SessionStateStoreProviderBase store = null;
            FieldInfo rqIdField = null, rqLockIdField = null, rqStateNotFoundField = null;

            //Iterating the fields in Session State Module object and assign the field values to local variables.
            foreach( System.Reflection.FieldInfo field in fields )
            {
                if( field.Name.Equals( "_store" ) )
                {
                    store = (System.Web.SessionState.SessionStateStoreProviderBase) field.GetValue( sessionStateModule );
                }
                if( field.Name.Equals( "_rqId" ) )
                {
                    rqIdField = field;
                }
                if( field.Name.Equals( "_rqLockId" ) )
                {
                    rqLockIdField = field;
                }
                if( field.Name.Equals( "_rqSessionStateNotFound" ) )
                {
                    rqStateNotFoundField = field;
                }
            }
            object lockId = rqLockIdField.GetValue( sessionStateModule );

            //Release the lock in the session data store.
            if( ( lockId != null ) && ( oldSessionId != null ) )
            {
                store.ReleaseItemExclusive( Context, oldSessionId, lockId );
            }
            rqStateNotFoundField.SetValue( sessionStateModule, true );
            rqIdField.SetValue( sessionStateModule, newSessionId );