Question

我如何创建一个函数，如果一个计数器保持5秒钟不变，那会发生什么？据我所知，我必须为旧的计数器值分配一个名称，然后再进行比较。这是正确的吗？

我的代码包含超时

 if (x1 && y1 && z1)
 {
    txtAngle.Text = "";
    txtDisplay.Text = "Number of times: " + counter + "\n" + "Go back to start position and repeat the exercise for " + databaseValue + " times";
    txtAgain.Text = "Go back to starting position.";
    txtAgain1.Text = "";
    counter++;

 // assign the old counter value as previous counter

        if (counter == previousCounter) // If the counter never increase for 5 seconds
        {
            timeout.Tick += timeout_TickAsync;
            timeout.Interval = TimeSpan.FromSeconds(5);
            timeout.Start();
        }
    timeangle1.Stop();
 }

超时功能

private void timeout_TickAsync(object sender, object e)
{
  // something happens.
    txtClock.Text = "HELLO WORLD";
    timeout.Stop();
}

此代码有一个错误，因为它不完整，Idk将从此处继续。有人，请帮助我。

Answer 1

您可以使用异步方法来处理。

void aync Task UpdateCounterAsync(int newValue)
{
    var oldValue = _counter;
    _counter = newValue;
    await Task.Delay(Timespan.FromSeconds(5));
    if (_counter == oldValue)
    {
        // counter is still the same; do something
    }
}

它将更新名为_counter的成员变量，等待5秒钟，并检查延迟后可用的值是否仍然相同。

如果您想提高弹性，还可以跟踪Task.Delay()返回的任务，并在每次进行新更新时将其取消。您将需要一个CancellationTokenSource成员变量，例如_cancellationTokenSource

void aync Task UpdateCounterAsync(int newValue)
{
    var oldValue = _counter;
    _counter = newValue;
    _cancellationSourceToken.Cancel();
    _cancellationSourceToken = new CancellationSourceToken();

    try
    {
        await Task.Delay(Timespan.FromSeconds(5), _cancellationSourceToken.Token);
        if (_counter == oldValue)
        {
            // counter is still the same; do something
        }
    }
    catch (TaskCancelledException)
    {
        // another update has been triggered while we were waiting. 
        // _counter has obviously changed then bail out
    }
}

C＃UWP（如果计数器在特定持续时间内保持不变）

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