你怎么跑在C＃中的同步计时器？ [英] How do you run a synchronous timer in C#?

问题描述

我写它使用一个计时器在屏幕上显示一个倒计时，当一些事件发生的应用程序。我想重新使用计时器，因为这将是很方便的在应用程序的几件事情，所以我指定我想包圆计时器的话。例如，下面的函数调用：

I am writing an app which uses a timer to display a countdown on screen to when some event happens. I want to reuse the timer, as it would be handy for a few things in the app, so I specify the words I want to wrap round the timer. For example, the following function call:

CountdownTimer(90, "You have ", " until the computer reboots");

会显示：

You have 1 minute 30 seconds until the computer reboots

，然后倒计时。

我用下面的code：

    private void CountdownTimer(int Duration, string Prefix, string Suffix)
    {
        Countdown = new DispatcherTimer();
        Countdown.Tick += new EventHandler(Countdown_Tick);
        Countdown.Interval = new TimeSpan(0, 0, 1);

        CountdownTime = Duration;
        CountdownPrefix = Prefix;
        CountdownSuffix = Suffix;
        Countdown.Start();
    }

    private void Countdown_Tick(object sender, EventArgs e)
    {
        CountdownTime--;
        if (CountdownTime > 0)
        {
            int seconds = CountdownTime % 60;
            int minutes = CountdownTime / 60;

            Timer.Content = CountdownPrefix;

            if (minutes != 0)
            {
                Timer.Content = Timer.Content + minutes.ToString() + @" minute";
                if (minutes != 1) { Timer.Content = Timer.Content + @"s"; }
                Timer.Content = Timer.Content + " ";
            }

            if (seconds != 0)
            {
                Timer.Content = Timer.Content + seconds.ToString() + @" second";
                if (seconds != 1) { Timer.Content = Timer.Content + @"s"; }
            }

            Timer.Content = Timer.Content + CountdownSuffix;

        }
        else
        {
            Countdown.Stop();
        }

    }

我如何使这个同步运行？例如，我想下面来等待90秒，然后重新启动：

How do I make this run synchronously? For example I would want the following to wait 90 seconds and then reboot:

CountdownTimer(90, "You have ", " until the computer reboots");
ExitWindowsEx(2,0)

，而当present立即调用重新启动。

Whereas it calls the reboot immediately at present.

任何指针将是最欢迎！

谢谢，

本

推荐答案

个人而言，我建议有一个回调发生在你CountdownTimer年底 - 也许服用动作作为参数，例如，当它完成它会被调用。

Personally, I'd recommend having a callback happen at the end of your CountdownTimer - perhaps taking an Action as an argument, such that when it completed it'd be called.

private Action onCompleted;
private void CountdownTimer(int Duration, string Prefix, string Suffix, Action callback)
{
    Countdown = new DispatcherTimer();
    Countdown.Tick += new EventHandler(Countdown_Tick);
    Countdown.Interval = new TimeSpan(0, 0, 1);

    CountdownTime = Duration;
    CountdownPrefix = Prefix;
    CountdownSuffix = Suffix;
    Countdown.Start();

    this.onCompleted = callback;
}
...
    else
    {
        Countdown.Stop();
        Action temp = this.onCompleted; // thread-safe test for null delegates
        if (temp != null)
        {
            temp();
        }
    }

然后，你可以只改变您的使用情况为：

Then you could just change your usage to:

CountdownTimer(90, "You have ", " until the computer reboots", 
    () => ExitWindowsEx(2,0));

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