how to group many radio buttons into 3 groups in C ?-CodePudding

My goal is to create 5 groups of radio buttons (i know it contradict with the title but you still get the point) for user choice using only Win32 API (so no window form here).

I tried using a combination of groupbox and SetWindowLongPtr but it still not working as expected (note that im using GWLP_WNDPROC as the index). If i use SetWindowLongPtr to a group box then that groupbox is gone and everything else work as expected.

I could use a "virtual" group box but it reduce the efficency of my code. Some one might recommend using WS_GROUP but it only apply if there are 2 group of radio buttons ( I think ). And i also dont like using resource so is there any solution to this problem or i just have to stuck with the "virtual" group box?

Minimal reproducible sample:

#include <Windows.h>
LRESULT CALLBACK WndProc(HWND hwnd, UINT uMsg, WPARAM wp, LPARAM lp)
{
    switch (uMsg)
    {
    default:
        return DefWindowProc(hwnd, uMsg, wp, lp);
    }
}
int WINAPI wWinMain(HINSTANCE hinst, HINSTANCE hiprevinst, PWSTR nCmdLine, int ncmdshow)
{
    const wchar_t CLASS_NAME[] = L"Sample";

    WNDCLASS wc = { };

    wc.lpfnWndProc = WndProc;
    wc.hInstance = hinst;
    wc.lpszClassName = CLASS_NAME;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);


    RegisterClass(&wc);
    HWND hwnd = CreateWindowEx(
        0,
        CLASS_NAME,
        L"Sample window",
        WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX | WS_MAXIMIZEBOX,            // Window style


        CW_USEDEFAULT, CW_USEDEFAULT, 800, 600,

        NULL,
        NULL,
        hinst,
        NULL);
    HWND groupbox = CreateWindowEx(0, L"Button", L"Groupbox", WS_VISIBLE | WS_CHILD | BS_GROUPBOX, 10, 10, 100, 100, NULL, NULL, hinst, NULL);
    HWND radiobutton1 = CreateWindowEx(0, L"Button", L"Groupbox", WS_VISIBLE | WS_CHILD | BS_AUTORADIOBUTTON, 10, 10, 60, 60, groupbox, NULL, hinst, NULL);
    SetWindowLongPtr(groupbox, GWLP_WNDPROC, (LONG)WndProc);
    SendMessage(groupbox, NULL, NULL, TRUE);
    ShowWindow(hwnd, ncmdshow);
    MSG msg;
    while (GetMessage(&msg, NULL, NULL, NULL))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return 0;
}

Due to i stripped so much of the necessary function away, you need to go to task manager and kill the process named "Autoclicker" for some reason to be able to recompile it again

CodePudding user response：

Make sure you handle WM_DESTROY otherwise window won't close properly.

The radio buttons, all child dialog items, and all child windows should be created in WM_CREATE section of parent window. They need the HWND handle from parent window.

SetWindowLongPtr(.. GWLP_WNDPROC ...) is an old method used for subclassing. Your usage is incorrect. You don't need it anyway.

It's unclear what SendMessage(groupbox, NULL, NULL, TRUE); is supposed to do.

Just add the radio buttons, make sure the first radio button has an added WS_TABSTOP|WS_GROUP as shown below

LRESULT CALLBACK WndProc(HWND hwnd, UINT uMsg, WPARAM wp, LPARAM lp)
{
    switch (uMsg)
    {
    case WM_CREATE:
    {
        HINSTANCE hinst = GetModuleHandle(0);

        auto add = [&](const wchar_t* name, 
            int id, int x, int y, int w, int h, bool first = false)
        {
            DWORD style = WS_VISIBLE | WS_CHILD | BS_AUTORADIOBUTTON;
            if (first) style |= WS_GROUP | WS_TABSTOP;
            return CreateWindowEx(0, L"Button", name, style,
                x, y, w, h, hwnd, (HMENU)id, hinst, NULL);
        };

        HWND groupbox1 = CreateWindowEx(0, L"Button", L"Groupbox1",
          WS_VISIBLE | WS_CHILD | BS_GROUPBOX, 2, 2, 250, 120, hwnd, NULL, hinst, NULL);
        HWND radio1 = add(L"radio1", 1, 10, 30, 200, 20, true);
        HWND radio2 = add(L"radio2", 2, 10, 51, 200, 20);
        HWND radio3 = add(L"radio3", 3, 10, 72, 200, 20);
        HWND radio4 = add(L"radio4", 4, 10, 93, 200, 20);

        HWND groupbox2 = CreateWindowEx(0, L"Button", L"Groupbox2",
          WS_VISIBLE | WS_CHILD | BS_GROUPBOX, 280, 2, 250, 120, hwnd, NULL, hinst, NULL);
        HWND radio11 = add(L"radio1", 11, 300, 30, 200, 20, true);
        HWND radio12 = add(L"radio2", 12, 300, 51, 200, 20);
        HWND radio13 = add(L"radio3", 13, 300, 72, 200, 20);
        HWND radio14 = add(L"radio4", 14, 300, 93, 200, 20);

        return 0;
    }

    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;

    default:
        return DefWindowProc(hwnd, uMsg, wp, lp);
    }
}
int WINAPI wWinMain(HINSTANCE hinst, HINSTANCE hiprevinst, PWSTR nCmdLine, int ncmdshow)
{
    const wchar_t CLASS_NAME[] = L"Sample";
    WNDCLASS wc = { };
    wc.lpfnWndProc = WndProc;
    wc.hInstance = hinst;
    wc.lpszClassName = CLASS_NAME;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    RegisterClass(&wc);
    HWND hwnd = CreateWindowEx(0, CLASS_NAME, L"Sample window",
        WS_OVERLAPPEDWINDOW, 0, 0, 800, 600,
        NULL, NULL, hinst, NULL);
    ShowWindow(hwnd, ncmdshow);
    MSG msg;
    while (GetMessage(&msg, NULL, NULL, NULL))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return 0;
}