如何异步等待 x 秒然后执行某些操作? [英] How to asynchronously wait for x seconds and execute something then?

问题描述

我知道有 Thread.Sleep 和 System.Windows.Forms.Timer 和 Monitor.Wait 在 C# 和 Windows 窗体中.我似乎无法弄清楚如何在不锁定线程的情况下等待 X 秒然后做其他事情.

I know there is Thread.Sleep and System.Windows.Forms.Timer and Monitor.Wait in C# and Windows Forms. I just can't seem to be able to figure out how to wait for X seconds and then do something else - without locking the thread.

我有一个带按钮的表单.单击按钮时，计时器应启动并等待 5 秒.在这 5 秒后，窗体上的其他一些控件变为绿色.使用 Thread.Sleep 时，整个应用程序将在 5 秒内无响应 - 那么我如何在 5 秒后做某事"?

I have a form with a button. On button click a timer shall start and wait for 5 seconds. After these 5 seconds some other control on the form is colored green. When using Thread.Sleep, the whole application would become unresponsive for 5 seconds - so how do I just "do something after 5 seconds"?

推荐答案

(从 Ben 作为评论转录)

(transcribed from Ben as comment)

只需使用 System.Windows.Forms.Timer.将定时器设置为 5 秒，并处理 Tick 事件.当事件触发时，做这件事.

just use System.Windows.Forms.Timer. Set the timer for 5 seconds, and handle the Tick event. When the event fires, do the thing.

...并在执行工作之前禁用计时器 (IsEnabled=false) 以抑制一秒钟.

...and disable the timer (IsEnabled=false) before doing your work in oder to suppress a second.

Tick 事件可能在另一个无法修改您的 gui 的线程上执行，您可以捕获:

The Tick event may be executed on another thread that cannot modify your gui, you can catch this:

private System.Windows.Forms.Timer myTimer = new System.Windows.Forms.Timer();

    private void StartAsyncTimedWork()
    {
        myTimer.Interval = 5000;
        myTimer.Tick += new EventHandler(myTimer_Tick);
        myTimer.Start();
    }

    private void myTimer_Tick(object sender, EventArgs e)
    {
        if (this.InvokeRequired)
        {
            /* Not on UI thread, reenter there... */
            this.BeginInvoke(new EventHandler(myTimer_Tick), sender, e);
        }
        else
        {
            lock (myTimer)
            {
                /* only work when this is no reentry while we are already working */
                if (this.myTimer.Enabled)
                {
                    this.myTimer.Stop();
                    this.doMyDelayedWork();
                    this.myTimer.Start(); /* optionally restart for periodic work */
                }
            }
        }
    }

<小时>

只是为了完整性:使用 async/await，可以很容易地延迟执行某些事情(一次，永远不要重复调用):

---

Just for completeness: with async/await, one can delay execute something very easy (one shot, never repeat the invocation):

private async Task delayedWork()
{
    await Task.Delay(5000);
    this.doMyDelayedWork();
}

//This could be a button click event handler or the like */
private void StartAsyncTimedWork()
{
    Task ignoredAwaitableResult = this.delayedWork();
}

有关更多信息，请参阅 MSDN 中的异步和等待".

For more, see "async and await" in MSDN.

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