代码之家 › 专栏 › 技术社区 › xvymnp

WM_HOTKEY消息未触发WinMain消息循环中的窗口大小调整

winapi c++

xvymnp · 技术社区 · 1 年前

#ifndef UNICODE
#define UNICODE
#endif

#define HOTKEY_REG_ERR -10

#define HOTKEY_DEC_ID 1
#define HOTKEY_INC_ID 2
#define HOTKEY_CEN_ID 3

#define WND_CHANGE_SIZE 50

#include <windows.h>

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
LRESULT CALLBACK WindowProcAlt(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
SHORT            ResizeWindow(HWND hwnd, int widthChange, int heightChange);

int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine, int nCmdShow) {
    // Register the window class.
    LPCWSTR mainWndClass = L"Sample Window Class ";

    WNDCLASS wc = {};

    wc.lpfnWndProc   = WindowProc;
    wc.hInstance     = hInstance;
    wc.lpszClassName = mainWndClass;

    RegisterClass(&wc);

    // Create the window.

    HWND hwnd = CreateWindowEx(
        0,                           // Optional window styles.
        mainWndClass,                // Window class
        L"Learn to Program Windows", // Window text
        WS_OVERLAPPEDWINDOW,         // Window style

        // Size and position
        CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,

        NULL,      // Parent window
        NULL,      // Menu
        hInstance, // Instance handle
        NULL       // Additional application data
    );

    if (hwnd == NULL) {
        return 0;
    }

    ShowWindow(hwnd, nCmdShow);

    // Register hotkeys

    BOOL resultOne   = 0;
    BOOL resultTwo   = 0;
    BOOL resultThree = 0;

    if (!RegisterHotKey(NULL, HOTKEY_DEC_ID, MOD_CONTROL | MOD_SHIFT, '1')) {
        resultOne = -1;
    }
    if (!RegisterHotKey(NULL, HOTKEY_INC_ID, MOD_CONTROL | MOD_SHIFT, '2')) {
        resultTwo = -2;
    }
    if (!RegisterHotKey(NULL, HOTKEY_CEN_ID, MOD_CONTROL | MOD_SHIFT, '3')) {
        resultThree = -3;
    }

    // Run the message loop

    MSG msg = {};

    while (GetMessage(&msg, NULL, 0, 0) > 0) {
        UINT messageCode = msg.message;
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return 0;
}

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
    switch (uMsg) {
        case WM_DESTROY:
            PostQuitMessage(0);
            return 0;

        case WM_PAINT: {
            PAINTSTRUCT ps;
            HDC         hdc = BeginPaint(hwnd, &ps);

            // All painting occurs here, between BeginPaint and EndPaint.

            FillRect(hdc, &ps.rcPaint, (HBRUSH) (COLOR_WINDOW + 1));

            EndPaint(hwnd, &ps);
        }
            return 0;

        case WM_HOTKEY:
            switch (wParam) {
                case HOTKEY_DEC_ID:
                    ResizeWindow(hwnd, -WND_CHANGE_SIZE, -WND_CHANGE_SIZE);
                    break;

                case HOTKEY_INC_ID:
                    ResizeWindow(hwnd, WND_CHANGE_SIZE, WND_CHANGE_SIZE);
                    break;

                case HOTKEY_CEN_ID:
                    break;

                default:
                    break;
            }
            return 0;
    }
    return DefWindowProc(hwnd, uMsg, wParam, lParam);
}

SHORT ResizeWindow(HWND hwnd, int widthChange, int heightChange) {
    if (hwnd == NULL) {
        return -1;
    }
    int  containerWidth, containerHeight, newWndWidth, newWndHeight, x, y;
    RECT rect;
    if (GetWindowRect(hwnd, &rect)) {
        RECT workArea = {};

        SystemParametersInfo(SPI_GETWORKAREA, NULL, &workArea, NULL);

        containerWidth  = workArea.right - workArea.left;
        containerHeight = workArea.bottom - workArea.top;

        newWndWidth  = rect.right - rect.left + widthChange;
        newWndHeight = rect.bottom - rect.top + heightChange;

        x = (containerWidth - newWndWidth) / 2;
        y = (containerHeight - newWndHeight) / 2;

        MoveWindow(hwnd, x, y, newWndWidth, newWndHeight, TRUE);
    } else {
        // std::cerr << "Failed to get window rect." << std::endl;
    }
}

起初,看起来WM_HOTKEY消息没有被发布。缺少窗口大小调整告诉了我这一点。我通过查看调试器中的resultOne、resultTwo和resultThree的值来确认我的密钥已正确注册,这些值都是0。然后我查看了消息循环,发现在消息循环中,msg.message成员是786=0x0312=WM_HOTKEY消息代码。也许我遗漏了一个线程问题?感谢您的帮助。

1 回复 | 直到 1 年前

Remy Lebeau 1 年前

你的 WindowProc 未接收 WM_HOTKEY 消息,因为您没有在窗口中注册热键。

这个 RegisterHotKey documentation 说:

参数

[in,可选]hWnd

类型:HWND

窗口的句柄,用于接收热键生成的WM_HOTKEY消息。 如果此参数为NULL,则WM_HOTKEY消息将被发布到调用线程的消息队列,并且必须在消息循环中进行处理。

...

评论

当按下某个键时,系统会查找与所有热键相匹配的项。找到匹配项后,系统将WM_HOTKEY消息发布到与热键相关联的窗口的消息队列。 如果热键与窗口不关联,则WM_HOTKEY消息将发布到与热键关联的线程。

线程消息没有 HWND 分配给它,因此没有的窗口过程 DispatchMessage() 将消息发送到。

因此,您必须处理 WM_HOTKEY 信息 直接地 在你的消息循环中(就像上面的文档所说的那样),例如:

while (GetMessage(&msg, NULL, 0, 0)) {
    if (msg.message == WM_HOTKEY) {
        // do something ...
    }
    else {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
}

否则,您将不得不执行以下操作之一,以便 WindowProc 可以接收 WM_HOTKEY 信息:

只需通过您的 HWND 到 RegisterHotKey() ,例如:
```
RegisterHotKey(hwnd, ...)
```

让您的消息循环转发消息到您的 HWND ,例如:

while (GetMessage(&msg, NULL, 0, 0)) {
    if (msg.message == WM_HOTKEY) {
        SendMessage(hwnd, msg.message, msg.wParam, msg.lParam);
    }
    else {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
}