来自按钮单击处理程序的 MFC 中的弹出菜单不起作用

Question

// CMFCApplication1Dlg dialog
CMFCApplication1Dlg::CMFCApplication1Dlg(CWnd* pParent /*=NULL*/)
    : CDialogEx(CMFCApplication1Dlg::IDD, pParent)
{
    m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CMFCApplication1Dlg::DoDataExchange(CDataExchange* pDX)
{
    CDialogEx::DoDataExchange(pDX);
}

BEGIN_MESSAGE_MAP(CMFCApplication1Dlg, CDialogEx)
    ON_WM_SYSCOMMAND()
    ON_WM_PAINT()
    ON_WM_QUERYDRAGICON()
    ON_BN_CLICKED(IDC_BUTTON1, &CMFCApplication1Dlg::OnBnClickedButton1)
END_MESSAGE_MAP()

// CMFCApplication1Dlg message handlers
BOOL CMFCApplication1Dlg::OnInitDialog()
{
    CDialogEx::OnInitDialog();

    // Add "About..." menu item to system menu.

    // IDM_ABOUTBOX must be in the system command range.
    ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
    ASSERT(IDM_ABOUTBOX < 0xF000);

    CMenu* pSysMenu = GetSystemMenu(FALSE);
    if (pSysMenu != NULL)
    {
        BOOL bNameValid;
        CString strAboutMenu;
        bNameValid = strAboutMenu.LoadString(IDS_ABOUTBOX);
        ASSERT(bNameValid);
        if (!strAboutMenu.IsEmpty())
        {
            pSysMenu->AppendMenu(MF_SEPARATOR);
            pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
        }
    }

    // Set the icon for this dialog.  The framework does this automatically
    //  when the application's main window is not a dialog
    SetIcon(m_hIcon, TRUE);         // Set big icon
    SetIcon(m_hIcon, FALSE);        // Set small icon

    // TODO: Add extra initialization here

    return TRUE;  // return TRUE  unless you set the focus to a control
}

void CMFCApplication1Dlg::OnSysCommand(UINT nID, LPARAM lParam)
{
    if ((nID & 0xFFF0) == IDM_ABOUTBOX)
    {
        CAboutDlg dlgAbout;
        dlgAbout.DoModal();
    }
    else
    {
        CDialogEx::OnSysCommand(nID, lParam);
    }
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CMFCApplication1Dlg::OnPaint()
{
    if (IsIconic())
    {
        CPaintDC dc(this); // device context for painting

        SendMessage(WM_ICONERASEBKGND, reinterpret_cast<WPARAM>(dc.GetSafeHdc()), 0);

        // Center icon in client rectangle
        int cxIcon = GetSystemMetrics(SM_CXICON);
        int cyIcon = GetSystemMetrics(SM_CYICON);
        CRect rect;
        GetClientRect(&rect);
        int x = (rect.Width() - cxIcon + 1) / 2;
        int y = (rect.Height() - cyIcon + 1) / 2;

        // Draw the icon
        dc.DrawIcon(x, y, m_hIcon);
    }
    else
    {
        CDialogEx::OnPaint();
    }
}

// The system calls this function to obtain the cursor to display while the user drags
// the minimized window.
HCURSOR CMFCApplication1Dlg::OnQueryDragIcon()
{
    return static_cast<HCURSOR>(m_hIcon);
}

void CMFCApplication1Dlg::OnBnClickedButton1()
{
    //Simulating the similar code as product
    CFrameWnd *pFrame = GetParentFrame();
    CMenu popup;
    popup.CreatePopupMenu();

    LPCWSTR pszMenuItem2 = L"Korean with wchar_t: 기존 운";
    AppendMenuW(popup.m_hMenu, MF_STRING, 1, pszMenuItem2);

    TCHAR* pszMenuItem3 = "|| Korean without wchar_t: 또는 차량 삽입";
    AppendMenu(popup.m_hMenu, MF_STRING, 2, pszMenuItem3);

    UINT nCmd = popup.TrackPopupMenu(TPM_LEFTALIGN | TPM_RIGHTBUTTON | TPM_RETURNCMD,
                                    14, 20, pFrame, 0);
}

我在上面写了一段代码，可以在点击按钮时在屏幕上生成弹出菜单，但它根本不显示任何菜单？我错过了什么吗？

如你所问，这里是完整的代码。实际上，我已经通过 GUI 放置了一个静态按钮，然后单击按钮尝试生成弹出菜单。

这些按钮不是动态创建的。此外，这里的整个代码都是由向导生成的，除了最后一部分关于按钮单击的代码。

Answer 1

问题出在句柄上，如果我使用正确的API获取句柄，它会显示弹出菜单。这是更新后的代码。

void CMFCApplication1Dlg::OnBnClickedButton1()
{
    //Simulating the similar code as product
    HWND wnd= GetSafeHwnd();//<---- this had to change  
    CMenu popup;
    popup.CreatePopupMenu();

    LPCWSTR pszMenuItem2 = L"Korean with wchar_t: 기존 운";
    AppendMenuW(popup.m_hMenu, MF_STRING, 1, pszMenuItem2);

    TCHAR* pszMenuItem3 = "|| Korean without wchar_t: 또는 차량 삽입";
    AppendMenu(popup.m_hMenu, MF_STRING, 2, pszMenuItem3);

    UINT nCmd = popup.TrackPopupMenu(TPM_LEFTALIGN | TPM_RIGHTBUTTON | TPM_RETURNCMD,
                                    14, 20, CWnd::FromHandle(wnd)/*need this api to get the CWnd from HWND*/, 0);

来自按钮单击处理程序的 MFC 中的弹出菜单不起作用

Popup menu in MFC from button click handler not working

visual-c++

mfc

popupmenu