Solved

Can WH_DEBUG hook detect when a hook is uninstalled

Posted on 2004-03-31
5
589 Views
Last Modified: 2013-12-03
I know that WH_DEBUG can detect when a hook is installed.  Does anybody know whether it can also detect when a hook is uninstalled?  If so, can you point me to a code sample which does such detection.  Thanks...
0
Comment
Question by:DanFromBoston
  • 3
5 Comments
 
LVL 16

Expert Comment

by:nonubik
ID: 10730447
I don't think so. And I don't think it can detect when a hook is installed.
MSDN states :
"WH_DEBUG Hook
The system calls a WH_DEBUG hook procedure before calling hook procedures associated with any other hook in the system. You can use this hook to determine whether to allow the system to call hook procedures associated with other types of hooks."

So nothing about (un)installation of a hook.
0
 
LVL 16

Expert Comment

by:nonubik
ID: 10730465
http://msdn.microsoft.com/library/en-us/winui/WinUI/WindowsUserInterface/Windowing/Hooks/AboutHooks.asp?frame=true#wh_debughook
I think you were missleaded by what says the MSDN for DebugProc wParam parameter (which I'm positive it's a copy-paste of the table from SetWindowsHookEx.. :)
0
 
LVL 5

Accepted Solution

by:
drnick earned 150 total points
ID: 10830860
you can do the following:

install a normal global hook
which, of course, involves that your dll is loaded in every app
your dll then, in its initialization code, replaces the normal UnhookWindowsHookEx by a
routine of the same signature which calls the "real" unhookwindowshookex proc but
also places a notification record in a shared memory section of your dll.
this record will then be read periodically by a thread in your application.

the whole thing is a little bit complicated, but it would work, maybe.
0
 
LVL 1

Author Comment

by:DanFromBoston
ID: 10832542
That's an interesting idea.  Are you sure that when you install a global hook that it's loaded into every app on the system?  I thought it was just loaded in the context of the thread you specify.
0
 
LVL 16

Assisted Solution

by:nonubik
nonubik earned 100 total points
ID: 10832567
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/WinUI/WindowsUserInterface/Windowing/Hooks/HookReference/HookFunctions/SetWindowsHookEx.asp

dwThreadId "If this parameter is zero, the hook procedure is associated with all existing threads running in the same desktop as the calling thread."
0

Featured Post

Free Tool: Postgres Monitoring System

A PHP and Perl based system to collect and display usage statistics from PostgreSQL databases.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

This article shows a few slightly more advanced techniques for Windows 7 gadget programming, including how to save and restore user settings for your gadget and how to populate the "details" panel that is displayed in the Windows 7 gadget gallery.  …
For a while now I'v been searching for a circular progress control, much like the one you get when first starting your Silverlight application. I found a couple that were written in WPF and there were a few written in Silverlight, but all appeared o…
This is Part 3 in a 3-part series on Experts Exchange to discuss error handling in VBA code written for Excel. Part 1 of this series discussed basic error handling code using VBA. http://www.experts-exchange.com/videos/1478/Excel-Error-Handlin…
This video shows how to quickly and easily add an email signature for all users on Exchange 2016. The resulting signature is applied on a server level by Exchange Online. The email signature template has been downloaded from: www.mail-signatures…

808 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question