Windows API 实现登录窗口

以下是使用Windows API实现登录窗口的示例代码：

#include <Windows.h>

// 定义窗口类名和标题
#define CLASS_NAME TEXT("LoginWindowClass")
#define WINDOW_TITLE TEXT("Login")

// 定义控件ID
#define ID_USERNAME 100
#define ID_PASSWORD 101
#define ID_LOGIN_BTN 102

// 定义控件位置和大小
#define USERNAME_X 50
#define USERNAME_Y 50
#define USERNAME_WIDTH 200
#define USERNAME_HEIGHT 25

#define PASSWORD_X 50
#define PASSWORD_Y 90
#define PASSWORD_WIDTH 200
#define PASSWORD_HEIGHT 25

#define LOGIN_BTN_X 100
#define LOGIN_BTN_Y 140
#define LOGIN_BTN_WIDTH 100
#define LOGIN_BTN_HEIGHT 30

// 定义全局变量
HWND g_hUsername, g_hPassword, g_hLoginBtn;

// 窗口过程函数
LRESULT CALLBACK LoginWindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch (msg)
    {
    case WM_CREATE:
        // 创建用户名输入框
        g_hUsername = CreateWindow(TEXT("EDIT"), NULL, WS_VISIBLE | WS_CHILD | WS_BORDER | ES_AUTOHSCROLL,
            USERNAME_X, USERNAME_Y, USERNAME_WIDTH, USERNAME_HEIGHT, hwnd, (HMENU)ID_USERNAME, NULL, NULL);
        // 创建密码输入框
        g_hPassword = CreateWindow(TEXT("EDIT"), NULL, WS_VISIBLE | WS_CHILD | WS_BORDER | ES_AUTOHSCROLL | ES_PASSWORD,
            PASSWORD_X, PASSWORD_Y, PASSWORD_WIDTH, PASSWORD_HEIGHT, hwnd, (HMENU)ID_PASSWORD, NULL, NULL);
        // 创建登录按钮
        g_hLoginBtn = CreateWindow(TEXT("BUTTON"), TEXT("Login"), WS_VISIBLE | WS_CHILD | BS_DEFPUSHBUTTON,
            LOGIN_BTN_X, LOGIN_BTN_Y, LOGIN_BTN_WIDTH, LOGIN_BTN_HEIGHT, hwnd, (HMENU)ID_LOGIN_BTN, NULL, NULL);
        break;

    case WM_COMMAND:
        if (LOWORD(wParam) == ID_LOGIN_BTN)
        {
            // 获取用户名和密码
            TCHAR szUsername[256], szPassword[256];
            GetWindowText(g_hUsername, szUsername, 256);
            GetWindowText(g_hPassword, szPassword, 256);
            // TODO: 进行登录验证
        }
        break;

    case WM_CLOSE:
        DestroyWindow(hwnd);
        break;

    case WM_DESTROY:
        PostQuitMessage(0);
        break;

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

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    // 注册窗口类
    WNDCLASS wc = { 0 };
    wc.lpfnWndProc = LoginWindowProc;
    wc.hInstance = hInstance;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wc.lpszClassName = CLASS_NAME;
    RegisterClass(&wc);

    // 创建窗口
    HWND hwnd = CreateWindow(CLASS_NAME, WINDOW_TITLE, WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT, 300, 220, NULL, NULL, hInstance, NULL);
    ShowWindow(hwnd, nCmdShow);

    // 消息循环
    MSG msg = { 0 };
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return (int)msg.wParam;
}

该代码使用了Windows API中的CreateWindow和GetWindowText等函数创建和操作窗口控件，实现了一个简单的登录窗口。在登录按钮被点击时，可以获取用户名和密码，并进行登录验证。需要注意的是，该代码中的登录验证部分尚未实现，需要根据具体需求进行编写。