正在阅读：深入探讨MFC消息循环和消息泵深入探讨MFC消息循环和消息泵

int CWnd::RunModalLoop(DWORD dwFlags)
{
 ASSERT(::IsWindow(m_hWnd)); // window must be created
 ASSERT(!(m_nFlags & WF_MODALLOOP)); // window must not already be in modal state

 // for tracking the idle time state
 BOOL bIdle = TRUE;
 LONG lIdleCount = 0;
 BOOL bShowIdle = (dwFlags & MLF_SHOWONIDLE) && !(GetStyle() & WS_VISIBLE);
 HWND hWndParent = ::GetParent(m_hWnd);
 m_nFlags |= (WF_MODALLOOP|WF_CONTINUEMODAL);
 MSG* pMsg = &AfxGetThread()->m_msgCur;

 // acquire and dispatch messages until the modal state is done
 for (;;)
 {
  ASSERT(ContinueModal());

  // phase1: check to see if we can do idle work
  while (bIdle &&
   !::PeekMessage(pMsg, NULL, NULL, NULL, PM_NOREMOVE))
  {
   ASSERT(ContinueModal());

   // show the dialog when the message queue goes idle
   if (bShowIdle)
   {
    ShowWindow(SW_SHOWNORMAL);
    UpdateWindow();
    bShowIdle = FALSE;
   }

   // call OnIdle while in bIdle state
   if (!(dwFlags & MLF_NOIDLEMSG) && hWndParent != NULL && lIdleCount == 0)
   {
    // send WM_ENTERIDLE to the parent
    ::SendMessage(hWndParent, WM_ENTERIDLE, MSGF_DIALOGBOX, (LPARAM)m_hWnd);
   }
   if ((dwFlags & MLF_NOKICKIDLE) ||
    !SendMessage(WM_KICKIDLE, MSGF_DIALOGBOX, lIdleCount++))
   {
    // stop idle processing next time
    bIdle = FALSE;
   }
  }

  // phase2: pump messages while available
  do
  {
   ASSERT(ContinueModal());

   // pump message, but quit on WM_QUIT
   //PumpMessage(消息泵)的实现和上面讲的差不多。都是派送消息到窗口。
   if (!AfxGetThread()->PumpMessage())
   {
    AfxPostQuitMessage(0);
    return -1;
   }

   // show the window when certain special messages rec'd
   if (bShowIdle &&
    (pMsg->message == 0x118 || pMsg->message == WM_SYSKEYDOWN))
   {
    ShowWindow(SW_SHOWNORMAL);