学习钩子的应用

在ATL组件编程中，弹出的非模态对话框无法响应某些键盘事件，一种解决办法是使用钩子：

CSDN的帖子：100分求救：Atl组件中键盘消息的响应问题

http://community.csdn.net/Expert/topic/5252/5252728.xml?temp=.8889887

改造后的实际应用：

// 存放非模态的对话框句柄

std::set<HWND> m_setHwnd;

static HHOOK hHook = NULL;

LRESULT FAR PASCAL GetMsgProc(int nCode, WPARAM wParam, LPARAM lParam)
{
 LPMSG lpMsg = (LPMSG) lParam;

 if ( nCode >= 0 && PM_REMOVE == wParam )
 {
  // Don't translate non-input events.
  if ( (lpMsg->message != WM_CHAR && lpMsg->message >= WM_KEYFIRST && lpMsg->message <= WM_KEYLAST) )
  {
   std::set<HWND>::iterator iter = m_setHwnd.begin();
   for (; iter != m_setHwnd.end(); iter++) {
    HWND hWnd = *iter;
    if ( IsDialogMessage(hWnd, lpMsg) )
    {
     // The value returned from this hookproc is ignored,
     // and it cannot be used to tell Windows the message has been handled.
     // To avoid further processing, convert the message to WM_NULL
     // before returning.
     lpMsg->message = WM_NULL;
     lpMsg->lParam  = 0;
     lpMsg->wParam  = 0;
    }
   }
  }
 }

 return CallNextHookEx(hHook, nCode, wParam, lParam);
}

// 钩子的植入

BOOL CXXXApp::InitInstance()
{
 AfxEnableControlContainer();
 hHook = SetWindowsHookEx( WH_GETMESSAGE, GetMsgProc,
  NULL, GetCurrentThreadId() );
    return CWinApp::InitInstance();
}

//钩子的卸载

int CXXXApp::ExitInstance()
{
 UnhookWindowsHookEx( hHook );
    return CWinApp::ExitInstance();
}