Win32Api Window 菜单激活问题

Question

运行我的程序它运行s 并且由于我有一个带有 EXIT 的菜单来销毁 window 它运行s 并立即退出 window.不确定如何在编译程序时解决我的问题，使其不是运行 WindowProcedure 函数并传递导致 Window 被破坏的参数 EXITMENU。

*.CPP

#include <windows.h>
#define HELPMENU 1
#define HIGHSCROREMENU 2
#define EXITMENU 3

int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR args, int ncmdshow) {
    WNDCLASS wc = { 0 }; // WNDCLASSW is a structure
    LPCWSTR title = L"Window"; // Long Pointer Constant Wide (UTF-16) String 

    wc.hbrBackground = (HBRUSH)COLOR_WINDOW; // Background
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL, IDC_HAND); // Sets Cursor
    wc.hInstance = hInst; // Instance of window
    wc.lpszClassName = L"windowClass"; // Class name
    wc.lpfnWndProc = WindowProcedure; // Pointer to the function // Controller of window handle

    if (!RegisterClassW(&wc)) { // Registers the window class
        return -1;
    }

    //                                                   | binary combination value, posX, posY, Width, Height

    // Creates the window
    CreateWindow(wc.lpszClassName, title, WS_OVERLAPPEDWINDOW | WS_VISIBLE | WS_BORDER, 100, 100, 800, 600, NULL, NULL, NULL, NULL);

    MSG msg = { 0 };


    while (GetMessage(&msg, NULL, NULL, NULL) > 0) { // Keeps the window running
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return 0;
}

/* Event Paths */
LRESULT CALLBACK WindowProcedure(HWND hWnd, UINT msg, WPARAM wp, LPARAM lp) {
    switch (msg) {
    case WM_CREATE: // On window creation
        AddControls(hWnd);
        AddMenu(hWnd);
        break;
    case WM_LBUTTONDOWN: // Left Mouse button
        break;
    case WM_DESTROY: // Makes GetMessage Function return false, closing the window
        PostQuitMessage(0);
        return 0;
    case EXITMENU:
        DestroyWindow(hWnd); // This part of the code shouldn't run on creation
        break;
    default:
        return DefWindowProc(hWnd, msg, wp, lp);
    }
}

/* Creates menu */
void AddMenu(HWND hWnd) {
    hMenu = CreateMenu(); // Creates menu object
    // AppendMenu(Menu Instance, Usage Type, Argument, String info);
    AppendMenu(hMenu, MF_STRING, HELPMENU, L"Help - F1");
    AppendMenu(hMenu, MF_STRING, HIGHSCROREMENU, L"Highscores - F2"); // Menu Created
    AppendMenu(hMenu, MF_STRING, EXITMENU, L"Exit - ESC");
    // SetMenu(Window Handle , Menu Instance);
    SetMenu(hWnd, hMenu); // Sets menu for window // 
}

Answer 1

您没有正确处理 WindowProcedure() 中的菜单命令。

您已将 EXITMENU 定义为 3，与 WM_MOVE 消息的值相同。因此，在您的 switch 中，您在 window 创建期间一收到 WM_MOVE 消息就销毁了 window。

根据文档，您需要通过 WM_COMMAND 消息来处理菜单命令：

About Menus: Messages Used With Menus

When the user chooses a command item from a menu, the system sends a WM_COMMAND message to the window procedure. The low-order word of the WM_COMMAND message's wParam parameter contains the identifier of the chosen item. The window procedure should examine the identifier and process the message accordingly.

试试这个：

LRESULT CALLBACK WindowProcedure(HWND hWnd, UINT msg, WPARAM wp, LPARAM lp) {
    switch (msg) {
        ...
        case WM_COMMAND:
            switch (wp) {
                case HELPMENU: {
                    ...
                    return 0;
                }
                case HIGHSCROREMENU: {
                    ...
                    return 0;
                }
                case EXITMENU: {
                    DestroyWindow(hWnd);
                    return 0;
                }
            }
            break;
        }
        ...
    }

    return DefWindowProc(hWnd, msg, wp, lp);
}

更新： 也就是说，考虑让您的 EXITMENU 处理程序使用 SendMessage(WM_CLOSE) 而不是 DestroyWindow()。如果您的应用保留在用户关闭应用时应保存的数据，您可以添加一个 WM_CLOSE 处理程序来执行该操作，而不管如何 window 正在关闭（您的退出菜单、X 关闭按钮、Alt-F4 等）。 DefWindowProc() 在处理 WM_CLOSE 时销毁一个 window。

LRESULT CALLBACK WindowProcedure(HWND hWnd, UINT msg, WPARAM wp, LPARAM lp) {
    switch (msg) {
        ...
        case WM_CLOSE: {
            if (data has been modified) {
                prompt user to save data...
                if (cancelled) {
                    return 0;
                }
                if (should save) {
                    save data ...
                }
            }
            break;
        }

        case WM_COMMAND:
            switch (wp) {
                ...
                case EXITMENU: {
                    SendMessage(hWnd, WM_CLOSE, 0, 0);
                    return 0;
                }
            }
            break;
        }
        ...
    }

    return DefWindowProc(hWnd, msg, wp, lp);
}

Win32Api Window 菜单激活问题

Win32Api Window Menu Activating issue

c++

windows

winapi

win32gui

win32-process