如何在 C # 4.0中使任务处于睡眠状态(或延迟) ？

using System;
using System.Threading;
using System.Threading.Tasks;


class Program
{
static void Main()
{
Delay(2000).ContinueWith(_ => Console.WriteLine("Done"));
Console.Read();
}


static Task Delay(int milliseconds)
{
var tcs = new TaskCompletionSource<object>();
new Timer(_ => tcs.SetResult(null)).Change(milliseconds, -1);
return tcs.Task;
}
}

来自 如何实现任务。延迟在4.0部分

您可以使用 Timer在4.0中创建 Delay方法:

public static Task Delay(double milliseconds)
{
var tcs = new TaskCompletionSource<bool>();
System.Timers.Timer timer = new System.Timers.Timer();
timer.Elapsed+=(obj, args) =>
{
tcs.TrySetResult(true);
};
timer.Interval = milliseconds;
timer.AutoReset = false;
timer.Start();
return tcs.Task;
}

您可以下载 异步 CTP并使用 TaskEx

使用来自 NuGet 的 微软包，它有 TaskEx.Delay。

下面是可取消 Task 的代码和示例工具。延迟执行。您可能对 Delay方法感兴趣:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


namespace DelayImplementation
{
class Program
{
static void Main(string[] args)
{
System.Threading.CancellationTokenSource tcs = new System.Threading.CancellationTokenSource();


int id = 1;
Console.WriteLine(string.Format("Starting new delay task {0}. This one will be cancelled.", id));
Task delayTask = Delay(8000, tcs.Token);
HandleTask(delayTask, id);


System.Threading.Thread.Sleep(2000);
tcs.Cancel();


id = 2;
System.Threading.CancellationTokenSource tcs2 = new System.Threading.CancellationTokenSource();
Console.WriteLine(string.Format("Starting delay task {0}. This one will NOT be cancelled.", id));
var delayTask2 = Delay(4000, tcs2.Token);
HandleTask(delayTask2, id);


System.Console.ReadLine();
}


private static void HandleTask(Task delayTask, int id)
{
delayTask.ContinueWith(p => Console.WriteLine(string.Format("Task {0} was cancelled.", id)), TaskContinuationOptions.OnlyOnCanceled);
delayTask.ContinueWith(p => Console.WriteLine(string.Format("Task {0} was completed.", id)), TaskContinuationOptions.OnlyOnRanToCompletion);
}


static Task Delay(int delayTime, System.Threading.CancellationToken token)
{
TaskCompletionSource<object> tcs = new TaskCompletionSource<object>();


if (delayTime < 0) throw new ArgumentOutOfRangeException("Delay time cannot be under 0");


System.Threading.Timer timer = null;
timer = new System.Threading.Timer(p =>
{
timer.Dispose(); //stop the timer
tcs.TrySetResult(null); //timer expired, attempt to move task to the completed state.
}, null, delayTime, System.Threading.Timeout.Infinite);


token.Register(() =>
{
timer.Dispose(); //stop the timer
tcs.TrySetCanceled(); //attempt to mode task to canceled state
});


return tcs.Task;
}
}
}

在许多情况下，纯粹的 AutoResetEvent 比 Thread.Sleep () ..。

AutoResetEvent pause = new AutoResetEvent(false);
Task timeout = Task.Factory.StartNew(()=>{
pause.WaitOne(1000, true);
});

希望能有所帮助

    public static void DelayExecute(double delay, Action actionToExecute)
{
if (actionToExecute != null)
{
var timer = new DispatcherTimer
{
Interval = TimeSpan.FromMilliseconds(delay)
};
timer.Tick += (delegate
{
timer.Stop();
actionToExecute();
});
timer.Start();
}
}

下面是一个简洁的、基于定时器的实现，并进行了适当的清理:

var wait = new TaskCompletionSource<bool>();
using (new Timer(_ => wait.SetResult(false), null, delay, Timeout.Infinite))
await wait.Task;

要在.NET 4.0上使用此代码，您需要 微软 NuGet 包。

从 回答延伸这个想法:

new AutoResetEvent(false).WaitOne(1000);