Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people, just like you, are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
Solved

Intercepting WM_KEYDOWN messages

Posted on 1998-08-12
5
487 Views
Last Modified: 2013-11-20
How do I intercept all WM_KEYDOWN messages regardless of which window they routed to ?
Basically I am trying to write an app which will run in the background and monitor all keystrokes and pop up a dialog when it receives a particular keystroke combination.
0
Comment
Question by:davidmurphy
5 Comments
 
LVL 1

Expert Comment

by:amby
ID: 1320637
You can change the window proc of each window you want to "trace", the instruction is SetWindowLong...

CMyWnd::OnWhatYouWant()
{
    //----- do it in every window you want to trace...
    OldWndProc = SetWindowLong(m_hWnd, GWL_WNDPROC, NewWndProc)
}

UINT NewWndProc (HWND, MESSAGE, LPARAM, WPARAM)
{
    //---- HWND identifies the window !!!

    //---- refer to online doc for exact syntax
    switch (MESSAGE) {
    case WM_KEYDOWN:
        ExecMyCode();
        break;
    }

    //---- It is often interesting...
    return CallWindowProc(OldWndProc,...);
}

Good luck
0
 

Author Comment

by:davidmurphy
ID: 1320638
Thank you for your answer but I dont think that it is quite what I am looking for.
Isn't there a way of hooking into the windows message queue in the same way (I imagine) that 'Spy' works ?

Thanks
0
 
LVL 1

Expert Comment

by:amby
ID: 1320639
I imagine Spy is modifying the window proc...

(in fac you can "empile" the window procs, very usefull !!)
0
 
LVL 3

Expert Comment

by:danny_pav
ID: 1320640
You want to look at HOOKs.
0
 
LVL 1

Accepted Solution

by:
arun_ta earned 100 total points
ID: 1320641
u might like to use Windows Message Hooks (Spy does that...) - except for a DOS window. Enough documentation is there in help files.

Another advanced method is to write a simple driver which intercepts the calls to windows kbd driver. (Visit sysinternals.com for an example)


0

Featured Post

Announcing the Most Valuable Experts of 2016

MVEs are more concerned with the satisfaction of those they help than with the considerable points they can earn. They are the types of people you feel privileged to call colleagues. Join us in honoring this amazing group of Experts.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
repeateFront java challenge 31 94
Looking for a specific application/software 2 114
Way to decrease size of apk file 9 87
Problem to Office 1 15
Introduction: Dialogs (1) modal - maintaining the database. Continuing from the ninth article about sudoku.   You might have heard of modal and modeless dialogs.  Here with this Sudoku application will we use one of each type: a modal dialog …
If you use Adobe Reader X it is possible you can't open OLE PDF documents in the standard. The reason is the 'save box mode' in adobe reader X. Many people think the protected Mode of adobe reader x is only to stop the write access. But this fe…
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.

828 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