MFC技巧

1

CFrameWnd::m_bAutoMenuEnable

说明：
当此成员是可用的（缺省），用户下拉一个菜单时，没有ON_COMMAND或ON_UPDATE_COMMAND_UI处理程序的菜单项目将被自动设置为无效。
具有ON_COMMAND处理程序而无ON_UPDATE_COMMAND_UI处理程序的菜单项目将被自动设置为可用。
当数据成员被设置时，菜单条与工具条按钮一样的方式被可用。
此数据成员简化了基于当前选择的最优命令的实现，并减少为可用与无效菜单项目编写ON_UPDATE_COMMAND_UI处理程序的应用需求。

 

2

static LPCSTR s_pszClassName = NULL;
    if(s_pszClassName == NULL)
    {
        WNDCLASS wndcls;
        ::GetClassInfo(AfxGetInstanceHandle(),cs.lpszClass,&wndcls);
        wndcls.style = CS_HREDRAW|CS_VREDRAW;
        wndcls.cbWndExtra = 0;
        wndcls.cbClsExtra = 0;
        wndcls.lpszMenuName = 0;
        wndcls.hbrBackground = (HBRUSH)GetStockObject(GRAY_BRUSH);
        wndcls.hCursor = LoadCursor(NULL,IDC_ARROW);
        wndcls.hIcon = 0;
        wndcls.lpszClassName = ND_PANEL_CLASS_NAME;

        VERIFY(AfxRegisterClass(&wndcls));
        s_pszClassName = ND_PANEL_CLASS_NAME;
    }

    cs.lpszClass = s_pszClassName;

 

 

3

 

BOOL SetThreadDesktopMFC(HDESK hDesk)
    {
        _AFX_THREAD_STATE* pState = AfxGetThreadState();
        BOOL bReHook = UnhookWindowsHookEx(pState->m_hHookOldMsgFilter);
        pState->m_hHookOldMsgFilter = NULL;
        BOOL bRet = ::SetThreadDesktop(hDesk);
        if(!bRet)
        {
            TRACE("SetThreadDesktopMFC fail:%u",GetLastError());
        }

        if(bReHook)
        {
            pState->m_hHookOldMsgFilter = SetWindowsHookEx(WH_MSGFILTER,MsgFilter,0,GetCurrentThreadId());
        }

        return bRet;
    }

    static LRESULT CALLBACK MsgFilter(int code,WPARAM wParam,LPARAM lParam)
    {
        CWinThread* pThread;
        if(afxContextIsDLL || (code<0 && code!=MSGF_DDEMGR) || ((pThread = AfxGetThread())==NULL))
        {
            return ::CallNextHookEx(_afxThreadState->m_hHookOldMsgFilter,code,wParam,lParam);
        }

        ASSERT(pThread != NULL);

        return (LRESULT)pThread->ProcessMessageFilter(code,(LPMSG)lParam);
    }