c# - 后台 worker 检查是否是午夜？

我想为WinForm创建一个后台工作程序，每当午夜过去时都会触发代码。

我对如何做有一个想法，但是我很确定这不是最好的方法。

while(1==1)
{
//if Datetime.Now == midnight, execute code
//sleep(1second)
}

最佳答案

使用System.Timers.Timer，在应用程序启动时，只需计算DateTime.Now和DateTime.Today.AddDays(0)之间的差即可。然后设置该时间间隔。

实际上，我最近做了一些类似的事情:

public static class DayChangedNotifier
{
    private static Timer timer;

    static DayChangedNotifier()
    {
        timer = new Timer(GetSleepTime());
        timer.Elapsed += (o, e) =>
            {
                OnDayChanged(DateTime.Now.DayOfWeek);
                timer.Interval = this.GetSleepTime();
            };
        timer.Start();

        SystemEvents.TimeChanged += new EventHandler(SystemEvents_TimeChanged);
    }

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

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

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

    public static event EventHandler<DayChangedEventArgs> DayChanged;
}

和:

public class DayChangedEventArgs : EventArgs
{
    public DayChangedEventArgs(DayOfWeek day)
    {
        this.DayOfWeek = day;
    }

    public DayOfWeek DayOfWeek { get; private set; }
}

用法:DayChangedNotified.DayChanged += ....