September 6, 2008 12:35pm pdt

1. evilrix 62,007
2. jkr 60,950
3. jaime_oliv... 45,143
4. TheLearn... 24,275
5. Gurudenis 24,085
6. DanRollins 23,100
7. AndyAins... 22,942
8. alb66 18,922
9. Infinity08 17,830
10. itsmeandn... 11,814
11. LordOfPo... 11,200
12. JohnGaby 9,550
13. roytal 6,536
14. josgood 5,300
15. Zoppo 4,975
16. Ichijo 4,600
16. bandyt1... 4,600
18. angelIII 4,000
18. SteveH_UK 4,000
18. mahesh1... 4,000
18. oxyoo 4,000
22. mjoachia... 3,875
23. DaveHowe 3,800
24. mitb 3,600
25. junges 3,500

1. AlexFM 494,078
2. lakshman... 273,989
3. jaime_oliv... 218,735
4. jkr 162,975
5. AndyAins... 137,865
6. nonubik 131,139
7. drichards 107,488
8. DanRollins 98,154
9. mahesh1... 75,401
10. evilrix 72,252
11. OnegaZh... 71,871
12. Svetlin_P... 69,175
13. itsmeandn... 58,382
14. Infinity08 52,317
15. Axter 50,719
16. khun 43,749
17. TheLearn... 36,875
18. rcarlan 35,440
19. ghergu 30,115
20. sunnycoder 28,810
21. Gurudenis 24,085
22. rajeev_d... 20,842
23. marcodal... 20,758
24. alb66 20,167
25. Jase-Co... 19,555

06.06.2008 at 07:26AM PDT, ID: 23463815

	[x] Attachment Details

Cancelling messages with CallWndProc

Asked by AndrewVos in Microsoft Visual C++.Net, Microsoft Visual C#.Net, Visual Studio 2008

Tags: C++ 2008, C# 2008

I've created a library in c++ 2008, which uses SetWindowsHookEx and CallWndProc.

I'm attempting to stop some messages from being processed, and can't seem to get it right.

I've trimmed the code down a bit, but basically all this code is in dllmain.

Also, I'm running StartHook and StopHook from a c# app using pinvoke.

I am definitely receiving the messages, which you can check by uncommenting the messagebox code at the bottom (be careful with this though, it will most likely crash your system. Try it in a virtual machine if you have to!)

Any ideas?Start Free Trial

         
           
             1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:
32:
33:
34:
35:
36:
37:
38:
39:
40:
41:
42:
43:
44:
45:
46:
47:
48:
49:
50:
51:
52:
53:
54:
55:
56:
57:

           
           
             // dllmain.cpp : Defines the entry point for the DLL application.
#include "stdafx.h"
 
LRESULT CALLBACK CallWndProc(int nCode,WPARAM wParam,LPARAM lParam);
HHOOK myHook = NULL;
HMODULE myModule = NULL;
 
extern "C" void _declspec(dllexport) StartHook(){
  if (myHook == NULL){
    myHook = SetWindowsHookEx(WH_CALLWNDPROC,(HOOKPROC)CallWndProc,myModule,0);
  }
}
extern "C" void _declspec(dllexport) StopHook(){
  if (myHook != NULL){
    UnhookWindowsHookEx(myHook);
  }
}
 
BOOL APIENTRY DllMain( HMODULE hModule, DWORD  ul_reason_for_call, LPVOID lpReserved){
  switch (ul_reason_for_call)	{
  case DLL_PROCESS_ATTACH:
    myModule = hModule;
    break;
  case DLL_THREAD_ATTACH:
    break;
  case DLL_THREAD_DETACH:
    break;
  case DLL_PROCESS_DETACH:
    StopHook();
    break;
  }
  return TRUE;
}
 
LRESULT CALLBACK CallWndProc(int nCode,WPARAM wParam,LPARAM lParam){
  if (nCode < 0){return CallNextHookEx(myHook,nCode,wParam,lParam);}
 
  BOOL cancelMessage = false;
 
  CWPSTRUCT* pwp = (CWPSTRUCT*)lParam;
 
  switch(pwp->message){
    case WM_SIZING:
      cancelMessage  = TRUE;
      break;
    case WM_SIZE:
      cancelMessage  = TRUE;
      break;
  }
 
  if (!cancelMessage){
    return CallNextHookEx(myHook,nCode,wParam,lParam);
  }else{
    return 1; //This doesn't work
   // MessageBox(0,L"Message Cancelled",L"Cancelled",MB_OK);
  }
}

           
         

Keywords: Cancelling messages with CallWndProc

	Title
1	MessageBox ,z-order
2	ASP.Net MessageBox
3	MessageBox in ASP.Net
4	Messagebox
5	Messagebox with text box
6	Track a messagebox

Loading Advertisement...

20080716-EE-VQP-32 / EE_QW_2_20070628

Cancelling messages with CallWndProc

Asked by AndrewVos in Microsoft Visual C++.Net, Microsoft Visual C#.Net, Visual Studio 2008

Tags: C++ 2008, C# 2008

About this solution