using System;

using System.Runtime.InteropServices;

using System.ComponentModel;

using System.Threading;



namespace Win32

{

    internal class HiPerfTimer

    {

        [DllImport("Kernel32.dll")]

        private static extern bool QueryPerformanceCounter(

            out long lpPerformanceCount);



        [DllImport("Kernel32.dll")]

        private static extern bool QueryPerformanceFrequency(

            out long lpFrequency);



        private long startTime, stopTime;

        private long freq;



        // 构造函数

        public HiPerfTimer()

        {

            startTime = 0;

            stopTime  = 0;



            if (QueryPerformanceFrequency(out freq) == false)

            {

                // 不支持高性能计数器

                throw new Win32Exception();

            }

        }



        // 开始计时器

        public void Start()

        {

            // 来让等待线程工作

            Thread.Sleep(0);



            QueryPerformanceCounter(out startTime);

        }



        // 停止计时器

        public void Stop()

        {

            QueryPerformanceCounter(out stopTime);

        }



        // 返回计时器经过时间(单位：秒)

        public double Duration

        {

            get

            {

                return (double)(stopTime - startTime) / (double) freq;

            }

        }

    }

}

HiPerfTimer pt = new HiPerfTimer();     // 创建新的 HiPerfTimer 对象

pt.Start();                             // 启动计时器

Console.WriteLine("Test\n");            // 需要计时的代码

pt.Stop();                              // 停止计时器

Console.WriteLine("Duration: {0} sec\n", 

     pt.Duration); // 打印需要计时部分代码的用时