Trigger an event when system locks/unlocks on Windows XP

Question

Please help me to find a way to track lock/unlock time on my WinXP machine. I've tried windows scheduler - it only logs logins, not locks. Any alternatives?

In Miranda's source code I saw implementation via IdleObject tracker, but this way is too long. May be an AutoIt script? Time tracking program (freeware)?

Answer 1

If you have a Windows service you can get notification of login/logout/lock/unlock events via the OnSessionChange method. In C# you would do this:

 protected override void OnSessionChange(SessionChangeDescription changeDescription)
 {
        switch (changeDescription.Reason)
        {
            case SessionChangeReason.SessionLogon:
                //Logon
                break;
            case SessionChangeReason.SessionLogoff:
                //Logoff
                break;
            case SessionChangeReason.RemoteConnect:
                //Remote Connect
                break;
            case SessionChangeReason.RemoteDisconnect:
                //Remote Disconnect
                break;
            case SessionChangeReason.SessionLock:
                //lock
                break;
            case SessionChangeReason.SessionUnlock:
                //Unlock
                break;
            default:
                break;
        }
 }