Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!decwrl!sgi!cdp!jeff
From: jeff@cdp.UUCP
Newsgroups: comp.windows.ms.programmer
Subject: Re: Windows Hooks
Message-ID: <1266500004@cdp>
Date: 9 Apr 91 03:24:00 GMT
References: <1823231@su92Z3w164w@ersys.uucp>
Lines: 17
Nf-ID: #R:su92Z3w164w@ersys.uucp:-182323169:cdp:1266500004:000:700
Nf-From: cdp.UUCP!jeff    Apr  8 20:24:00 1991


> I'm having a little trouble with hooks.  I understand that all of the
> hook code has to be out in a DLL.  I've written the hook, I can get it
> to work after installing it, but when I uninstall it, it sends my machine
> into BRS land.  Hard reboot time.


When you invoke UnhookWindowsHook, your hook routine may be invoked
one last time (with the first argument, nCode, set to -1).  You must
be prepared to handle this case: in particular, you must not call
FreeProcInstance until the unhook is complete; and (as mentioned in
the documentation) when you see that nCode is -1, you should invoke
DefHookProc without doing any other processing.

	Jeff Dean
	jeff@cdp.igc.org
	uunet!pyramid!cdp!jeff