Microsoft KB Archive/104122

Detecting Logoff from a Service

PSS ID Number: Q104122 Article last modified on 11-02-1995

3.10 3.50

WINDOWS NT

Sometimes it is handy for a service to know whether or not a user is logged on to the system. For example, suppose that there are circumstances under which the service displays a dialog box and waits for the user to respond. If this is done while the user is logged off, the service is blocked until the user logs on again.

Unfortunately, there is no direct way for a service to detect whether or not a user is logged on. There is, however, an indirect method. If you supply MB_DEFAULT_DESKTOP_ONLY as one of the flags in the fuStyle parameter of MessageBox, the function will fail if no one is logged on or if a screen saver is running.

Additional reference words: 3.10 3.50 KBCategory: kbprg KBSubcategory: BseService ============================================================================= Copyright Microsoft Corporation 1995.