Java Stopwatch类,性能与时间计时器案例详解

static void Main(string[] args)
        {
            Stopwatch sw = new Stopwatch();
            sw.Start();     //开始计时
            WebClient wc = new WebClient();
            string str = wc.DownloadString("http://www.jmeii.com/");
            Console.WriteLine(sw.IsRunning);    //输出 true   计时器是否在运行。
            sw.Stop();      //计时结束
            Console.WriteLine(sw.Elapsed);      //输出 00:00:00.3452873
            Console.WriteLine(sw.ElapsedMilliseconds);  //输出 223
            Console.WriteLine(sw.ElapsedTicks); //输出501838
            Console.WriteLine(sw.IsRunning);    //输出 flase

            Console.WriteLine(Stopwatch.GetTimestamp());   //输出56151531319  获取计时器机制中的当前最小时间单位数。

            sw.Reset(); //重置
            Console.WriteLine(sw.Elapsed.ToString());   //输出 00:00:00   //返回的是TimeSpan类型，可以任意处理

            sw.Restart();   //重新开始
            FileStream fs = new FileStream(@"D:\admin_b.txt", FileMode.Open, FileAccess.Read);
            //string str = 
            byte[] byteArr = new byte[fs.Length];
            fs.Read(byteArr, 0, (int)fs.Length);
            Stopwatch sw2 = Stopwatch.StartNew();       //创建一个新的计时器
            string str2 = Encoding.UTF8.GetString(byteArr);
            sw.Stop();
            Console.WriteLine(sw.ElapsedMilliseconds);  //输出 10
            Console.WriteLine(sw2.ElapsedMilliseconds); //输出 9
            sw2.Stop();
            
            Console.ReadKey();
        }

static void Main(string[] args)
        {
            Stopwatch sw = new Stopwatch();
            sw.Start();
            FileStream fs = new FileStream(@"D:\admin_b.txt", FileMode.Open, FileAccess.Read);
            //string str = 
            byte[] byteArr = new byte[fs.Length];
            fs.Read(byteArr, 0, (int)fs.Length);
            string str = Encoding.UTF8.GetString(byteArr);
            sw.Stop();
            Console.WriteLine(sw.ElapsedMilliseconds);  //输出 12

            Stopwatch sw2 = new Stopwatch();
            sw2.Start();
            File.ReadAllText(@"E:\admin_b.txt");
            sw2.Stop();
            Console.WriteLine(sw2.ElapsedMilliseconds); //输出 11

            Console.ReadKey();
        }

public class Program
    {
        static void Main(string[] args)
        {
            //获取到一个随机数集合
            List<int> ListInt = new List<int>();
            Random r = new Random();
            for (int i = 0; i < 1000000; i++)       //生成一个1百万数字的集合
            {
                ListInt.Add(r.Next(1000));
            }

            Stopwatch sw = new Stopwatch();
            sw.Start();
            int count = 0;
            foreach (var i in ListInt)
            {
                count = count + i;          
            }
            Console.WriteLine("遍历计算结果：" + count);       
            sw.Stop();
            Console.WriteLine("遍历用时：" + sw.ElapsedMilliseconds);    //输出 13

            Stopwatch sw2 = new Stopwatch();
            sw2.Start();
            int count2 = 0;
            count2 = ListInt.Sum();
            Console.WriteLine("Linq的计算结果：" + count2);
            Console.WriteLine("Linq的使用时间：" + sw2.ElapsedMilliseconds);  //输出 12
            sw2.Stop();

            Console.ReadKey();
        }
    }