m_msgCur 在 Visual Studio 2019

Question

我目前正在将旧源代码转移到 Visual Studio 2019。

原始代码来自 VC++6 或更早版本。

在WindowsMFC中，有一个叫做CWinThread的class，根据旧的源代码，m_msgCur存在于class中。但是，在VS2019中，它说 m_msgCur 不存在。然后发现m_msgCur早就存在了（https://github.com/dblock/msiext/blob/master/externals/WinDDK/7600.16385.1/inc/mfc42/afxwin.h，MFC 4.2），在VS2019中被删除了。 MSG m_msgCur 包含线程的当前消息，但是VS2019中是否有任何替代变量？

// message pump for Run
MSG m_msgCur;                   // current message

已编辑：

项目 link：https://github.com/ValveSoftware/halflife/tree/master/utils/serverctrl

Class CServerCtrlDlg（继承自CDialog）在ServerCtrlDlg.h中声明。 ServerCtrlDlg.cpp 包含其工作原理。 ServerCtrlClg.cpp 包含 <afxpriv.h>，<afxpriv.h> 包含 afxwin.h，后者有 CWinThread.

使用m_msgCur

的ServerCtrlDlg的一部分

int CServerCtrlDlg::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());

        int iRet = RMLPreIdle();

        if (iRet < 0)
            goto ExitModal;
        else if (iRet > 0)
            continue;

        // 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
        {
            BOOL ShouldPump = TRUE;

            ASSERT(ContinueModal());

            // See if we are requiring messages to be in queue?
            if ( m_bOnlyPumpIfMessageInQueue )
            {
                // If there isn't a message, don't turn over control to PumpMessage
                //  since it will block
                if ( !::PeekMessage( pMsg, NULL, NULL, NULL, PM_NOREMOVE ) )
                {
                    ShouldPump = FALSE;
                }
            }

            // pump message, but quit on WM_QUIT
            if ( ShouldPump )
            {
                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);
                    UpdateWindow();
                    bShowIdle = FALSE;
                }

                if (!ContinueModal())
                    goto ExitModal;

                // reset "no idle" state after pumping "normal" message
                if (AfxGetThread()->IsIdleMessage(pMsg))
                {
                    bIdle = TRUE;
                    lIdleCount = 0;
                }
            }

        } while (::PeekMessage(pMsg, NULL, NULL, NULL, PM_NOREMOVE));
    }
ExitModal:
    m_nFlags &= ~(WF_MODALLOOP|WF_CONTINUEMODAL);
    return m_nModalResult;
}

Answer 1

简答是替换：

    MSG* pMsg = &AfxGetThread()->m_msgCur;  // vc++ 6

与：

    MSG *pMsg = AfxGetCurrentMessage();     // vc++ 2019

但是，更好的答案是，如果您必须破解CWnd::RunModalLoop，那么您应该正确地做，并更新CServerCtrlDlg::RunModalLoop以使其基于来自 VC++ 2019 的当前 CWnd::RunModalLoop 代码，而不是从 VC++ 6.

借用的旧代码

将 CServerCtrlDlg::RunModalLoop 与 mfc\src\wincore.cpp 的 VC++ 6 中的 CWnd::RunModalLoop 实现进行比较，显示以下标有 //++ 的行已添加。

int CServerCtrlDlg::RunModalLoop(DWORD dwFlags)
{
//...
    // acquire and dispatch messages until the modal state is done
    for (;;)
    {
        ASSERT(ContinueModal());

        int iRet = RMLPreIdle();                                                    //++
                                                                                    //++
        if (iRet < 0)                                                               //++
            goto ExitModal;                                                         //++
        else if (iRet > 0)                                                          //++
            continue;                                                               //++

        // phase1: check to see if we can do idle work
        while (bIdle &&
            !::PeekMessage(pMsg, NULL, NULL, NULL, PM_NOREMOVE))
        {
            ASSERT(ContinueModal());
//...
//...
        // phase2: pump messages while available
        do
        {
            ASSERT(ContinueModal());

            BOOL ShouldPump = TRUE;                                                 //++
                                                                                    //++
            // See if we are requiring messages to be in queue?                     //++
            if ( m_bOnlyPumpIfMessageInQueue )                                      //++
            {                                                                       //++
                // If there isn't a message, don't turn over control to PumpMessage //++
                //  since it will block                                             //++
                if ( !::PeekMessage( pMsg, NULL, NULL, NULL, PM_NOREMOVE ) )        //++
                {                                                                   //++
                    ShouldPump = FALSE;                                             //++
                }                                                                   //++
            }                                                                       //++

            if ( ShouldPump )                                                       //++
            {
                /* mfc code executed conditionally */
            }
//...
}

CServerCtrlDlg::RunModalLoop 应更新为使用 VC++ 2019 CWnd::RunModalLoop 代码，然后将那些 //++ 行合并到其中。 CWnd::RunModalLoop 中的 MFC 变化在两个版本之间足够小，合并很简单。

m_msgCur 在 Visual Studio 2019

m_msgCur in Visual Studio 2019

mfc

visual-studio

visual-c++