How properly hook WM_COMMAND - c++

Question

I'm trying to hook a button click in a mfc window.And I used WM_COMMAND and WM_NOTIFY.For test, if the button is clicked, the hook must create a messagebox. The problem is that it doesn't react to button clicks.
Here's the code for reacting to WM_COMMAND and WM_NOTIFY:
LPMSG msg = (LPMSG)lParam;
switch( msg->message )
{
case WM_COMMAND:
MessageBox( NULL,"HOOK","YOOOO",MB_ICONEXCLAMATION );
break;
case WM_NOTIFY:
MessageBox( NULL,"HOOK","YOOOOO",MB_ICONEXCLAMATION );
break;
}
And here's the code to hole dll:
#include <Windows.h>
#include "FindingWindow.h"
#pragma comment( linker,"/SECTION:.SHARED,RWS" )
#pragma data_seg( ".SHARED" )
CaptureTextWindow* ctw;
HHOOK hook = 0;
HMODULE hInstance = 0;
HWND hWndServer = NULL;
#pragma data_seg()
static LRESULT CALLBACK msghook(int nCode, WPARAM wParam, LPARAM lParam);
__declspec(dllexport) BOOL clearMyHook(HWND hWnd);
BOOL APIENTRY DllMain( HINSTANCE hInst, DWORD ul_reason_for_call, LPVOID lpReserved )
{
switch( ul_reason_for_call )
{
case DLL_PROCESS_ATTACH:
hInstance = hInst;
return TRUE;
case DLL_PROCESS_DETACH:
if(hWndServer != NULL)
clearMyHook(hWndServer);
return TRUE;
}
return TRUE;
}
__declspec(dllexport) BOOL WINAPI setMyHook(HWND hWnd)
{
if(hWndServer != NULL)
return FALSE;
hook = SetWindowsHookEx(
WH_CALLWNDPROC,
(HOOKPROC)msghook,
hInstance,
0);
if(hook != NULL)
{ /* success */
hWndServer = hWnd;
return TRUE;
} /* success */
return FALSE;
}
__declspec(dllexport) BOOL clearMyHook(HWND hWnd)
{
if(hWnd != hWndServer)
return FALSE;
BOOL unhooked = UnhookWindowsHookEx(hook);
if(unhooked)
hWndServer = NULL;
return unhooked;
}
static LRESULT CALLBACK msghook( int nCode, // hook code
WPARAM wParam , // message identifier
LPARAM lParam )
{
if( nCode < 0 )
{
CallNextHookEx( hook, nCode, wParam, lParam );
return 0;
}
LPMSG msg = (LPMSG)lParam;
switch( msg->message )
{
case WM_COMMAND:
MessageBox( NULL,"HOOK","YOOOO",MB_ICONEXCLAMATION );
break;
case WM_NOTIFY:
MessageBox( NULL,"HOOK","YOOOOO",MB_ICONEXCLAMATION );
break;
}
return CallNextHookEx( hook, nCode, wParam, lParam );
}
I used not only WM_COMMAND cause I thought mb it will work, but it didn't.Thanks for answer.

Answer 1

The lParam for a WH_CALLWNDPROC hook is of type CWPSTRUCT. Your CallWndProc should look like this:
// ...
const CWPSTRUCT& cwps = *(CWPSTRUCT*)lParam;
switch ( cwps.message ) {
case WM_COMMAND:
MessageBox( ... );
break;
// ...