DateChange在午夜举行的活动

Question

可能重复:
背景工人在午夜时检查？

是否有一个我可以注册的SystemEvent,它将在午夜发布,当日期发生变化时？

Answer 1

这是我用来处理这个问题的一个类.它类似于@sll的答案,但考虑到系统时间的变化,也会触发每个午夜而不是一次.

static class MidnightNotifier
{
    private static readonly Timer timer;

    static MidnightNotifier()
    {
        timer = new Timer(GetSleepTime());
        timer.Elapsed += (s, e) =>
        {
            OnDayChanged();
            timer.Interval = GetSleepTime();
        };
        timer.Start();

        SystemEvents.TimeChanged += OnSystemTimeChanged;
    }

    private static double GetSleepTime()
    {
        var midnightTonight = DateTime.Today.AddDays(1);
        var differenceInMilliseconds = (midnightTonight - DateTime.Now).TotalMilliseconds;
        return differenceInMilliseconds;
    }

    private static void OnDayChanged()
    {
        var handler = DayChanged;
        if (handler != null)
            handler(null, null);
    }

    private static void OnSystemTimeChanged(object sender, EventArgs e)
    {
        timer.Interval = GetSleepTime();
    }

    public static event EventHandler<EventArgs> DayChanged;
}

由于它是静态类,您可以使用以下代码订阅事件:

MidnightNotifier.DayChanged += (s, e) => { Console.WriteLine("It's midnight!"); };