Re: Question regarding SetWindowsHookEx

From:

"William DePalo [MVP VC++]" <willd.no.spam@mvps.org>

Newsgroups:

microsoft.public.vc.language

Date:

Fri, 30 Mar 2007 14:29:55 -0400

Message-ID:

<u$bNLmvcHHA.588@TK2MSFTNGP06.phx.gbl>

"SergioQ" <sergio@warptv.com> wrote in message
news:1175275305.328060.72000@n59g2000hsh.googlegroups.com...

My dox say the following:

Remarks
An error may occur if the hMod parameter is NULL and the dwThreadId
parameter is zero or specifies the identifier of a thread created by
another process.

So when I tried hooking a thread created by another process, it
worked. So am curious what determines it failing or not? Just cause
it works on my machine doesn't mean it will work on all.

Anyone know? Thanks ahead,

What does it mean to hook a thread? If you explain what you did, we'll be in
a better position to vet it.

If you don't understand the documentation then what it is basically saying
is that if you need a hook procedure to trap events that occur outside of
the thread which planted the hook, then the hook procedure must reside in a
DLL.

If the hook procedure resides in a DLL, then you must specify the instance /
module handle to the DLL when you plant the hook.

As module handles of DLLs represent the base address at which they are
loaded, the handle can never be zero.

Regards,
Will
www.ivrforbeginners.com