<div>
You can change the window proc of each window you want to &quot;trace&quot;, the instruction is SetWindowLong...<br />
<br />
CMyWnd::OnWhatYouWant()<br />
{<br />
&nbsp; &nbsp; //----- do it in every window you want to trace...<br />
&nbsp; &nbsp; OldWndProc = SetWindowLong(m_hWnd, GWL_WNDPROC, NewWndProc)<br />
}<br />
<br />
UINT NewWndProc (HWND, MESSAGE, LPARAM, WPARAM)<br />
{<br />
&nbsp; &nbsp; //---- HWND identifies the window !!!<br />
<br />
&nbsp; &nbsp; //---- refer to online doc for exact syntax<br />
&nbsp; &nbsp; switch (MESSAGE) {<br />
&nbsp; &nbsp; case WM_KEYDOWN:<br />
&nbsp; &nbsp; &nbsp; &nbsp; ExecMyCode();<br />
&nbsp; &nbsp; &nbsp; &nbsp; break;<br />
&nbsp; &nbsp; }<br />
<br />
&nbsp; &nbsp; //---- It is often interesting...<br />
&nbsp; &nbsp; return CallWindowProc(OldWndProc,<wbr />...);<br />
}<br />
<br />
Good luck<br />

</div>


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


<div>
Thank you for your answer but I dont think that it is quite what I am looking for.<br />
Isn't there a way of hooking into the windows message queue in the same way (I imagine) that 'Spy' works ?<br />
<br />
Thanks<br />

</div>


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


<div>
I imagine Spy is modifying the window proc...<br />
<br />
(in fac you can &quot;empile&quot; the window procs, very usefull !!)<br />

</div>


I imagine Spy is modifying the window proc...

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


<div>
You want to look at HOOKs.<br />

</div>


<div>
<div class="content wysiwyg-content">
How do I intercept all WM_KEYDOWN messages regardless of which window they routed to ?<br />
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. 
</div>
</div>


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. 

Intercepting WM_KEYDOWN messages

Kernel and system programming is the process of creating the software necessary for a computer or device to function and operate other programs. Some operating systems (such as Microsoft Windows) are proprietary, but others, such as the various Linux distributions, are open source.