【Demo 0029】截取同进程窗体消息

今天这个话题比较简单，仅截取同进程的窗体消息，如果我们再做一些处理做成一个DLL然后将DLL驻入到指定进程的窗体中那更有意思了， 我们将在后面的章节里再研究一下。 我们开始学习了。 本节与上一节都在讲述着同相的内容围绕着GetWindowLongPtr, SetWindowLongPtr两个API进行的

(一) 函数声明

      LONG_PTR GetWindowLongPtr(HWND hWnd, int nIndex );

      LONG_PTR SetWindowLongPtr(HWND hWnd, int nIndex, LONG_PTR dwNewLong );

      获取/修改Window窗体信息值

     

      Code1:  通过修改窗体过程函数来截取窗体消息

     1.  为了保存原窗体过程函数， 我们将它到设置USER_DATA位，实现各函数数据共享;

     2.  通过SetWindowLongPtr, 来设置新的窗体过程函数;    

if (!bHook)
{
    TCHAR szTmp[MAX_PATH];
    TCHAR szClsName[MAX_PATH];
    GetClassName(hWnd, szClsName, MAX_PATH);
    WNDCLASSEX wcx    = {0};
    wcx.cbSize        = sizeof(WNDCLASSEX);
    
    SetWindowText(GetDlgItem(hWnd, ID_BTNHOOKMSG), _T("Stop Hook"));
    OutputDebugString(_T("\n============== Start Hook Message ================\n"));
    
    GetClassInfoEx(GetModuleHandle(NULL), szClsName, &wcx);
    _stprintf_s(szTmp, _T("WndProc Value before SetWindowLongPtr: 0x%0X  ==> 0x%0X\n"), wcx.lpfnWndProc, GetWindowLongPtr(hWnd, GWLP_WNDPROC));
    OutputDebugString(szTmp);

    SetWindowLongPtr(hWnd, GWLP_USERDATA, (LONG)WndProc);
    SetWindowLongPtr(hWnd, GWLP_WNDPROC, (LONG)_HookWndProc);

    GetClassInfoEx(GetModuleHandle(NULL), szClsName, &wcx);
    _stprintf_s(szTmp, _T("WndProc Value After SetWindowLongPtr: 0x%0X  ==> 0x%0X\n"), wcx.lpfnWndProc, GetWindowLongPtr(hWnd, GWLP_WNDPROC));
    OutputDebugString(szTmp);
    OutputDebugString(_T("==================================================================\n"));
    bHook = true;
} else {
    SetWindowText(GetDlgItem(hWnd, ID_BTNHOOKMSG), _T("Start Hook"));
    OutputDebugString(_T("\n============== Stop Hook Message ================\n"));
    SetWindowLongPtr(hWnd, GWLP_USERDATA, (LONG)0);
    SetWindowLongPtr(hWnd, GWLP_WNDPROC, (LONG)WndProc);
    bHook = false;
}

    3.  在新的窗体过程函数中打印被截取消息

   

//////////////////////////////////////////////////////////////////////////
LRESULT CALLBACK _HookWndProc(HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam)
{
    TCHAR szTemp[256];
    _stprintf_s(szTemp, _T("[HookProc msg] => hWnd: 0x%06X  nMsg: %06X  wParam: 0x%06X  lParam: 0x%06X\n"),
                hWnd, nMsg, wParam, lParam);
    OutputDebugString(szTemp);

    WNDPROC _oldWndProc = (WNDPROC)GetWindowLongPtr(hWnd, GWLP_USERDATA);
    if (NULL == _oldWndProc)    
    {
        _oldWndProc = (WNDPROC)GetClassLongPtr(hWnd, GCLP_WNDPROC);
    }
    return _oldWndProc(hWnd, nMsg, wParam, lParam);
}

   演示结果:

   1.  没修改窗体过程前

[WndProc msg] => hWnd: 0x010BBA  nMsg: 000020  wParam: 0x010BBA  lParam: 0x2000012
[WndProc msg] => hWnd: 0x010BBA  nMsg: 0000A0  wParam: 0x000012  lParam: 0x282023C
[WndProc msg] => hWnd: 0x010BBA  nMsg: 0002A2  wParam: 0x000000  lParam: 0x000000
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000086  wParam: 0x000000  lParam: 0x000000
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000006  wParam: 0x000000  lParam: 0x000000
[WndProc msg] => hWnd: 0x010BBA  nMsg: 00001C  wParam: 0x000000  lParam: 0x001B10
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000008  wParam: 0x000000  lParam: 0x000000
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000281  wParam: 0x000000  lParam: 0xC000000F
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000282  wParam: 0x000001  lParam: 0x000000

   2.   修改窗体过程之后

============== Start Hook Message ================
WndProc Value before SetWindowLongPtr: 0x8C11B8  ==> 0x8C11B8
WndProc Value After SetWindowLongPtr: 0x8C11B8  ==> 0x8C10DC
==================================================================
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000111  wParam: 0x0003E9  lParam: 0x010BBE
[HookProc msg] => hWnd: 0x010BBA  nMsg: 000020  wParam: 0x010BBE  lParam: 0x2000001
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000020  wParam: 0x010BBE  lParam: 0x2000001
[HookProc msg] => hWnd: 0x010BBA  nMsg: 000020  wParam: 0x010BBE  lParam: 0x2000001
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000020  wParam: 0x010BBE  lParam: 0x2000001
[HookProc msg] => hWnd: 0x010BBA  nMsg: 000020  wParam: 0x010BBE  lParam: 0x2000001

  3.  恢复原窗体过程

============== Stop Hook Message ================
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000111  wParam: 0x0003E9  lParam: 0x010BBE
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000020  wParam: 0x010BBE  lParam: 0x2000001
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000020  wParam: 0x010BBE  lParam: 0x2000001
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000020  wParam: 0x010BBE  lParam: 0x2000001
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000020  wParam: 0x010BBE  lParam: 0x2000001
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000020  wParam: 0x010BBE  lParam: 0x2000001
[WndProc msg] => hWnd: 0x010BBA  nMsg: 000020  wParam: 0x010BBE  lParam: 0x2000001

(二) 特别说明

    演示的代码里我们也在设置窗体过程函数前后打印了WNDCLASSEX类信息， 也发布我们设置的窗体过程并没有修改了WNDCLASS wndProc;

 

演示代码