你如何在C＃中运行同步计时器？

我正在编写一个应用程序，它使用计时器在某些事件发生时在屏幕上显示倒计时。 我想重用计时器，因为它对应用程序中的一些东西很方便，所以我指定了我想要围绕计时器的单词。 例如，以下函数调用：

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。

我使用以下代码：

  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(); } } 

如何同步运行？ 例如，我希望以下等待90秒，然后重新启动：

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

而目前它立即调用重启。

任何指针都是最受欢迎的！

谢谢，

本

Answer 1

就个人而言，我建议在CountdownTimer结束时进行回调 – 也许将Action作为参数，这样当它完成时就会被调用。

 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(); } } 

然后你可以改变你的用法：

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

Answer 2

您可以使用AutoResetEvent：

 System.Threading.AutoResetEvent _countdownFinishedEvent = new AutoResetEvent(false); 

在CountdownTimer结束时添加：

 _countdownFinishedEvent.WaitOne(); 

在Countdown.Stop()之后将其添加到Countdown_Tick的else中：

 _countdownFinishedEvent.Set();