如何使子菜单在 C++ 中执行 onclick 功能

Question

我正在尝试在任何程序窗口的顶部制作一个带有子菜单的简单菜单，它可以在单击子菜单时执行您想要的任何功能，例如您单击菜单，它会打开“子菜单”，您单击子菜单，它会执行此功能，其中使用 SetWindowTextA 更改窗口的标题。

SetWindowTextA(ROBLOX, "a"); // we set the text of the window title to whatever you want, in this case "a"


        HMENU SubSX = CreatePopupMenu(); //Create a submenu which appears on hovering to "menu" called "Sub-Menu"

        AppendMenu(SX, MF_POPUP | MF_STRING, (UINT_PTR)SubSX, "Sub-Menu");


        HMENU SX = CreateMenu(); //Create the main menu ontop of a window called "Menu"

        AppendMenu(SX, MF_POPUP | MF_STRING, (UINT_PTR)SubSX, "Menu");


        SetMenu(ROBLOX, SX);

正如您在上面的代码中看到的，我创建了一个菜单，其中包含一个名为 Sub-Menu 的子菜单 ROBLOX 是窗口的句柄，现在不是我们关心的问题

正在使用的菜单和子菜单：

所以，我基本上想要做的是，当您单击子菜单时，例如上图中的“子菜单”，它会执行特定功能（例如：使用 SetWindowText 更改窗口标题）

我知道它需要某种窗口挂钩，但我不知道如何，需要任何帮助。

提前致谢。

Answer 1

首先，您可以创建一个标识符来确定要控制的菜单项，例如#define IDM_SUBSX 1001。

然后使用AppendMenu通过标识符指定菜单项：AppendMenu(SubSX, MF_STRING, IDM_SUBSX, "Sub-Menu");。

最后通过WM_COMMAND消息确定菜单项的标识，我们可以根据标识对不同的菜单项做不同的操作。

这里是示例：

#include <Windows.h>
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
#define IDM_SUBSX 1001
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow)
{
    static TCHAR szAppName[] = TEXT("hello windows");
    HWND hwnd;
    MSG msg;
    WNDCLASS wndclass;
    wndclass.style = CS_HREDRAW | CS_VREDRAW;
    wndclass.lpfnWndProc = WndProc;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.hInstance = hInstance;
    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndclass.lpszMenuName = NULL;
    wndclass.lpszClassName = szAppName;
    if (!RegisterClass(&wndclass))
    {
        MessageBox(NULL, TEXT("This program requires Windows NT!"), szAppName, MB_ICONERROR);
    }

    hwnd = CreateWindow(szAppName,
        TEXT("the hello program"),
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        NULL,
        NULL,
        hInstance,
        NULL);
    ShowWindow(hwnd, iCmdShow);
    UpdateWindow(hwnd);

    while (GetMessageW(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessageW(&msg);
    }
    return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    HDC hdc;
    PAINTSTRUCT ps;
    RECT rect;

    switch (message)
    {
    case WM_CREATE:
    {
        SetWindowTextA(hwnd, "a"); // we set the text of the window title to whatever you want, in this case "a"

        HMENU SX = CreateMenu();
        HMENU SubSX = CreatePopupMenu(); //Create a submenu which appears on hovering to "menu" called "Sub-Menu"
        AppendMenu(SubSX, MF_STRING, IDM_SUBSX, "Sub-Menu");
        AppendMenu(SX, MF_POPUP | MF_STRING, (UINT_PTR)SubSX, "Menu");

        SetMenu(hwnd, SX);
        return 0;
    }
    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        GetClientRect(hwnd, &rect);
        DrawTextW(hdc, (L"Hello,Windows"), -1, &rect, DT_SINGLELINE | DT_CENTER | DT_VCENTER);
        EndPaint(hwnd, &ps);
        return 0;
    case WM_COMMAND:
        switch (LOWORD(wParam))
        {
        case IDM_SUBSX:
            SetWindowTextA(hwnd, "TITLE CHANGED"); 
            return 0;
        default:
            break;
        };

        return 0;
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
}