c++ / 具有多个单独窗口的应用程序

Question

所以我有这个创建两个窗口的代码：

WNDCLASS wc;
    wc.style = CS_BYTEALIGNCLIENT | CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = StaticWndProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = (HINSTANCE)GetModuleHandle(nullptr);
    wc.hCursor = LoadCursor(nullptr, IDC_ARROW);
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION); 
    wc.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
    wc.lpszMenuName = nullptr;
    wc.lpszClassName = _T("Move Engine");
    RegisterClass(&wc);
    m_hWnd = CreateWindow("Move Engine", "Move Engine", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, usWidth, usHeight, nullptr, nullptr, wc.hInstance, this);

    // Create the settings window
    wc.lpszClassName = _T("Settings");
    RegisterClass(&wc);
    s_hWnd = CreateWindow("Settings", "Settings", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 800, 20, nullptr, nullptr, wc.hInstance, this);

ShowWindow(m_hWnd, SW_SHOW);
ShowWindow(s_hWnd, SW_SHOW);

问题是，每次我关闭一个窗口时，应用程序都会终止。我需要的是两个独立的窗口；主应用程序窗口和一个可以访问应用程序各种设置的窗口 - 因此关闭设置窗口不应影响主窗口。有没有办法实现这一目标？谢谢。

---

附：我的 WinMain 函数修改如下：

int WINAPI WinMain(HINSTANCE a_hInstance, HINSTANCE a_hPrevInstance, LPTSTR a_lpCmdLine, int a_iCmdShow)
{
    int iReturnCode;

    // Initialise the engine.
    if (!MyEngine.InitInstance(a_hInstance, a_lpCmdLine, a_iCmdShow)) return 0;

    // Begin the gameplay process and return when the application due to exit
    iReturnCode = MyEngine.StartEngine();

    // Return the correct exit code.
    return iReturnCode;
}

StaticWndProc 看起来像这样：

LRESULT CALLBACK CMoveEngine::StaticWndProc(HWND hWnd, UINT Message, WPARAM wParam, LPARAM lParam)
{
    // If this is a create message, trap the 'this' pointer passed in and store it within the window.
    if (Message == WM_CREATE) SetWindowLong(hWnd, GWL_USERDATA, (LONG)((CREATESTRUCT FAR *)lParam)->lpCreateParams);

    // Obtain the correct destination for this message
    CMoveEngine *Destination = (CMoveEngine*)GetWindowLong(hWnd, GWL_USERDATA);

    // If the hWnd has a related class, pass it through
    if (Destination) return Destination->DisplayWndProc(hWnd, Message, wParam, lParam);

    // No destination found, defer to system...
    return DefWindowProc(hWnd, Message, wParam, lParam);
}

消息循环：

int CMoveEngine::StartEngine()
{
    MSG msg;
// Start main loop
while (true) 
{
    // Did we recieve a message, or are we idling?
    if (PeekMessage(&msg, nullptr, 0, 0, PM_REMOVE)) 
    {
        if (msg.message == WM_QUIT) break;
        TranslateMessage(&msg);
        DispatchMessage (&msg);
    } 
    else 
    {

    }
}

return 0;
}

Answer 1

您使用相同的lpfnWndProc 注册两个窗口类。因此，所有消息（包括鼠标点击和键盘按下）都将被定向到相同的函数StaticWndProc。

因此，当此函数接收到WM_CLOSE message 时，它会通过销毁窗口来响应，从而停止消息泵并终止程序。由于两个窗口具有相同的消息处理函数，它们都会以相同的方式响应。

解决方案是定义两个不同的WndProc 方法，一个用于您的每个窗口，或者处理WM_CLOSE 消息的特殊情况，只为您要允许关闭的窗口调用DefWindowProc整个应用程序。

Answer 2

使您的StaticWndProc 处理WM_CLOSE 或WM_DESTROY：在这种情况下，它应该减少openedWindows 计数器。如果该计数器达到零，请调用PostQuitMessage。