后台工作者检查是否是午夜? [英] Background Worker Check For When It's Midnight?

问题描述

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.

I want to create a background worker for a WinForm that triggers code whenever midnight rolls by.

我对操作方法有所了解，但我敢肯定这不是最好的方法.

I have an idea of how to do it, but I'm pretty sure it's not the best way to do it.

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

推荐答案

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.

Use a System.Timers.Timer and at application start up just calculate the difference between DateTime.Now and DateTime.Today.AddDays(0). Then set the interval for that amount.

我最近实际上做了这样的事情:

I actually did something just like this recently:

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;
}

AND:

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

    public DayOfWeek DayOfWeek { get; private set; }
}

用法:DayChangedNotified.DayChanged += ....

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