В: Как я могу открыть окно из окна с помощью кнопок в C ++?

Question

Я недавно начал изучать C ++ и хочу создать окно с кнопкой, открывающее другое окно с большим количеством кнопок. Вот что я пробовал:

//some more code 

    if (LOWORD(param) == Settings) {

#define a 1
#define b 2


            const char* CLASS_NAME = "Settings";
            WNDCLASS se{};
            se.hInstance = currentInstance;
            se.lpszClassName = CLASS_NAME;
            se.hCursor = LoadCursor(nullptr, IDC_ARROW);
            se.hbrBackground = (HBRUSH)COLOR_WINDOW;
            se.lpfnWndProc = WindowProcessMessages;
            RegisterClass(&se);

            CreateWindow(CLASS_NAME, "Settings", WS_OVERLAPPEDWINDOW | WS_VISIBLE, CW_USEDEFAULT, CW_USEDEFAULT, 800, 600, nullptr, nullptr, nullptr, nullptr);
            return 0;
                switch (msg) {
                case WM_CREATE: {
                    CreateWindow(TEXT("button"), TEXT("test"),
                        WS_VISIBLE | WS_CHILD,
                        020, 530, 70, 15,
                        hwnd, (HMENU)a, NULL, NULL);

                    CreateWindow(TEXT("button"), TEXT("ok"),
                        WS_VISIBLE | WS_CHILD,
                        720, 530, 50, 15,
                        hwnd, (HMENU)b, NULL, NULL);
                    break;
                }
            }

    }
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    default:
        return DefWindowProc(hwnd, msg, param, lparam);
    }
}

Answer 1

Во-первых, вам нужно создать новый winpro c для дочернего окна («Настройки») и поместить обработку сообщения (кнопка создания) в этот дочерний winpro c.

И, вам не нужно регистрировать дочернее окно («Настройки») каждый раз, когда вы получаете сообщение WM_COMMAND> Settings. Вы можете разместить регистрацию класса окна «Настройки» вместе с регистрацией класса главного окна.

Пример был: (Используйте Windows шаблон настольного приложения в Visual Studio 2019)

#define MAX_LOADSTRING 100
#define ID_SETTINGS 2
// Global Variables:
HINSTANCE hInst;                                // current instance
WCHAR szTitle[MAX_LOADSTRING];                  // The title bar text
WCHAR szWindowClass[MAX_LOADSTRING];            // the main window class name

// Forward declarations of functions included in this code module:
ATOM                MyRegisterClass(HINSTANCE hInstance);
ATOM                RegisterSettingsClass(HINSTANCE hInstance);
BOOL                InitInstance(HINSTANCE, int);
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK    SettingsProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK    About(HWND, UINT, WPARAM, LPARAM);

int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
                     _In_opt_ HINSTANCE hPrevInstance,
                     _In_ LPWSTR    lpCmdLine,
                     _In_ int       nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);

    // TODO: Place code here.

    // Initialize global strings
    LoadStringW(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
    LoadStringW(hInstance, IDC_WINDOWSPROJECT8, szWindowClass, MAX_LOADSTRING);
    MyRegisterClass(hInstance);
    RegisterSettingsClass(hInstance);
    // Perform application initialization:
    if (!InitInstance (hInstance, nCmdShow))
    {
        return FALSE;
    }

    HACCEL hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_WINDOWSPROJECT8));

    MSG msg;

    // Main message loop:
    while (GetMessage(&msg, nullptr, 0, 0))
    {
        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return (int) msg.wParam;
}



//
//  FUNCTION: MyRegisterClass()
//
//  PURPOSE: Registers the window class.
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
    WNDCLASSEXW wcex;

    wcex.cbSize = sizeof(WNDCLASSEX);

    wcex.style          = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc    = WndProc;
    wcex.cbClsExtra     = 0;
    wcex.cbWndExtra     = 0;
    wcex.hInstance      = hInstance;
    wcex.hIcon          = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_WINDOWSPROJECT8));
    wcex.hCursor        = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName   = MAKEINTRESOURCEW(IDC_WINDOWSPROJECT8);
    wcex.lpszClassName  = szWindowClass;
    wcex.hIconSm        = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

    return RegisterClassExW(&wcex);
}

ATOM RegisterSettingsClass(HINSTANCE hInstance)
{
    WNDCLASSEXW wcex;

    wcex.cbSize = sizeof(WNDCLASSEX);

    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc = SettingsProc;
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;
    wcex.hInstance = hInstance;
    wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_WINDOWSPROJECT8));
    wcex.hCursor = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wcex.lpszMenuName = MAKEINTRESOURCEW(IDC_WINDOWSPROJECT8);
    wcex.lpszClassName = L"Settings";
    wcex.hIconSm = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

    return RegisterClassExW(&wcex);
}
//
//   FUNCTION: InitInstance(HINSTANCE, int)
//
//   PURPOSE: Saves instance handle and creates main window
//
//   COMMENTS:
//
//        In this function, we save the instance handle in a global variable and
//        create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   hInst = hInstance; // Store instance handle in our global variable

   HWND hWnd = CreateWindowW(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
      CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, nullptr, nullptr, hInstance, nullptr);
   HWND hbutton = CreateWindow(TEXT("button"), TEXT("test"),
       WS_VISIBLE | WS_CHILD,
       020, 530, 70, 15,
       hWnd, (HMENU)ID_SETTINGS, NULL, NULL);
   if (!hWnd)
   {
      return FALSE;
   }

   ShowWindow(hWnd, nCmdShow);
   UpdateWindow(hWnd);

   return TRUE;
}

#define a 1
#define b 2

LRESULT CALLBACK SettingsProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_CREATE:
    {
        CreateWindow(TEXT("button"), TEXT("test"),
            WS_VISIBLE | WS_CHILD,
            020, 530, 70, 15,
            hWnd, (HMENU)a, NULL, NULL);

        CreateWindow(TEXT("button"), TEXT("ok"),
            WS_VISIBLE | WS_CHILD,
            720, 530, 50, 15,
            hWnd, (HMENU)b, NULL, NULL);
    }
    break;
    case WM_COMMAND:
    {
        int wmId = LOWORD(wParam);
        // Parse the menu selections:
        switch (wmId)
        {
        case a:
            MessageBox(hWnd,L"test",L"message",NULL);
            break;
        case b:
            MessageBox(hWnd, L"ok", L"message", NULL);
            break;
        default:
            return DefWindowProc(hWnd, message, wParam, lParam);
        }
    }
    break;
    case WM_PAINT:
    {
        PAINTSTRUCT ps;
        HDC hdc = BeginPaint(hWnd, &ps);
        // TODO: Add any drawing code that uses hdc here...
        EndPaint(hWnd, &ps);
    }
    break;
    case WM_DESTROY:
        DestroyWindow(hWnd);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}
//
//  FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  PURPOSE: Processes messages for the main window.
//
//  WM_COMMAND  - process the application menu
//  WM_PAINT    - Paint the main window
//  WM_DESTROY  - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_COMMAND:
        {
            int wmId = LOWORD(wParam);
            // Parse the menu selections:
            switch (wmId)
            {
            case IDM_ABOUT:
                DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
                break;
            case IDM_EXIT:
                DestroyWindow(hWnd);
                break;
            case ID_SETTINGS:
            {
                HWND hwnd = CreateWindow(L"Settings", L"Settings", WS_OVERLAPPEDWINDOW | WS_VISIBLE, CW_USEDEFAULT, CW_USEDEFAULT, 800, 600, nullptr, nullptr, nullptr, nullptr);
                ShowWindow(hwnd, SW_SHOW);
                UpdateWindow(hwnd);
            }
                break;
            default:
                return DefWindowProc(hWnd, message, wParam, lParam);
            }
        }
        break;
    case WM_PAINT:
        {
            PAINTSTRUCT ps;
            HDC hdc = BeginPaint(hWnd, &ps);
            // TODO: Add any drawing code that uses hdc here...
            EndPaint(hWnd, &ps);
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

// Message handler for about box.
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    UNREFERENCED_PARAMETER(lParam);
    switch (message)
    {
    case WM_INITDIALOG:
        return (INT_PTR)TRUE;

    case WM_COMMAND:
        if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
        {
            EndDialog(hDlg, LOWORD(wParam));
            return (INT_PTR)TRUE;
        }
        break;
    }
    return (INT_PTR)FALSE;
}

Для обучения Win32 вы можете обратиться к следующему документу:

Начало работы с Win32 и C ++

Справочник по программированию для Win32 API