我正在尝试在 x-a 和 x-b 的绝对值大于 150 时重置计时器。

Question

此代码用于计算计时器给出的信息。我希望它激活时，定时是有效的，我希望计时器重置时，某些标准发生。我想让代码不断检查这些参数。X, a, b不断变化

Stopwatch sw = new Stopwatch(); //sets sw as the stopwatch variable
sw.Start(); //starts stopwatch
for (int i = 0; ; i++) //counter
{
     if (i % 1000000 == 0) //sets counter limit
     {
          sw.Stop();  //stops stopwatch
          if (sw.ElapsedMilliseconds >= 3000)  //when the elapsed time is > 3 secs
          {
              comPort.WriteLine("1"); //sends a 1 to an arduino 
              break; //breaks for loop
          }
          else if (sw.ElapsedMilliseconds < 3000) //when the elapsed time is < 3 secs
          {
              if ((Math.Abs(x-a) < 150) && (Math.Abs(x-b) < 150)) //criteria to start
              {
                  sw.Start(); //continues stopwatch
              }
              else if ((Math.Abs(x-a) > 150) && (Math.Abs(x-b) > 150)) //criteria reset
              {
                  sw.Reset(); //resets stopwatch
                  break; //breaks for loop
              }
          }
     }
}

Answer 1

我看到一个明显的问题——秒表基本上在整个循环中都停止了。它不会做任何类似计时的事情

Answer 2

我在这里看到的一个重要标志是，您通过迭代for循环来轮询秒表。这会占用不必要的CPU资源。最好是切换到事件驱动系统，使用System.Timers.Timer对象，并按照逻辑指示启用它们。下面是上面例子中使用计时器实现的逻辑。设置一个定时器，每500毫秒检查一次x的值，并相应开启3秒定时器。

using System;
using System.Timers;
public class HelloWorld
{
    static int a = 0, x = 0, b = 100;
    static Timer timerOut, timerCheck;
    static public void Main()
    {
        timerOut = new Timer(3000);
        timerOut.Elapsed += new ElapsedEventHandler(OnOutElapsed);
        timerCheck = new Timer(500); 
        timerCheck.Elapsed += new ElapsedEventHandler(OnCheckElapsed);
        timerCheck.Start();
        for(;;) {
            Console.WriteLine("Input x or (Q)uit");
            string s = Console.ReadLine();
            if(s.ToLower() == "q") break;
            x = Convert.ToInt32(s);
        }
    }
    private static void OnCheckElapsed(object sender, ElapsedEventArgs e)
    {
        if((Math.Abs(x-a) < 150) && (Math.Abs(x-b) < 150)) {
            if(!timerOut.Enabled) {
                Console.WriteLine("starting timer (x={0})",x);
                timerOut.Start(); 
            }
        }
        else if((Math.Abs(x-a) > 150) && (Math.Abs(x-b) > 150)) {
            if(timerOut.Enabled) {
                Console.WriteLine("stopping timer (x={0})",x);
                timerOut.Stop();
            }
        }
    }
    private static void OnOutElapsed(object sender, ElapsedEventArgs e) 
    {
        Console.WriteLine("write to com port");
    }
}