注册电气工程师考试倒计时程序

#include 
#include 
#include 
#include 

time_t end;

void CenterWindow(HWND hWnd_self)
{
    HWND hWnd_parent;
    RECT rw_self, rc_parent, rw_parent;
    int xpos, ypos;

    hWnd_parent = GetParent(hWnd_self);
    if (NULL == hWnd_parent)
        hWnd_parent = GetDesktopWindow();

    GetWindowRect(hWnd_parent, &rw_parent);
    GetClientRect(hWnd_parent, &rc_parent);
    GetWindowRect(hWnd_self, &rw_self);

    xpos = rw_parent.left + (rc_parent.right + rw_self.left - rw_self.right) / 2;
    ypos = rw_parent.top + (rc_parent.bottom + rw_self.top - rw_self.bottom) / 2;

    SetWindowPos(
        hWnd_self, NULL,
        xpos, ypos, 0, 0,
        SWP_NOSIZE | SWP_NOZORDER | SWP_NOACTIVATE
    );

    struct tm t;

    t.tm_year = 2025 - 1900;
    t.tm_mon = 11 - 1;
    t.tm_mday = 1;
    t.tm_hour = 8;
    t.tm_min = 0;
    t.tm_sec = 0;

    end = mktime(&t);
}

// 窗口处理函数
LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    HDC hdc;
    PAINTSTRUCT ps;
    RECT rect;
    TCHAR buf[128];

    time_t start;
    int nday, nhour, nmin, nsec, diff;

    switch (uMsg)
    {
    case WM_CREATE:
        SetTimer(hWnd, 10, 500, NULL);
        CenterWindow(hWnd);
        break;
    case WM_TIMER:
        InvalidateRect(hWnd, NULL, TRUE);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    case WM_PAINT:
        hdc = BeginPaint(hWnd, &ps);
        GetClientRect(hWnd, &rect);

        time(&start);
        diff = (int)difftime(end, start);

        nday = diff / (24 * 3600);
        nhour = (diff - nday * 24 * 3600) / 3600;
        nmin = (diff - nday * 24 * 3600) % 3600 / 60;
        nsec = (diff - nday * 24 * 3600) % 3600 % 60;

        _stprintf_s(buf, 128, TEXT("%d天%02d时%02d分%02d秒"), nday, nhour, nmin, nsec);
        DrawText(hdc, buf, -1, &rect, DT_SINGLELINE | DT_CENTER | DT_VCENTER);
        EndPaint(hWnd, &ps);
        break;
    }
    return DefWindowProc(hWnd, uMsg, wParam, lParam);
}

INT WINAPI _tWinMain(
    _In_ HINSTANCE hInstance,
    _In_opt_ HINSTANCE hPrevInstance,
    _In_ LPTSTR lpCmdLine,
    _In_ INT nShowCmd)
{
    WNDCLASS wc;
    HWND hWnd;
    MSG msg;

    // 注册窗口类
    ZeroMemory(&wc, sizeof(wc));
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = WndProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInstance;
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wc.lpszMenuName = NULL;
    wc.lpszClassName = TEXT("BasicWindow");

    RegisterClass(&wc);

    // 创建窗口
    hWnd = CreateWindow(TEXT("BasicWindow"), TEXT("注电倒计时"),
        WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU, 0, 0, 240, 120, NULL, NULL, hInstance, NULL);

    // 显示窗口
    ShowWindow(hWnd, nShowCmd);
    UpdateWindow(hWnd);

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

    return (int)msg.wParam;
}