C#如何测试代码运行时间

// example1: System.DateTime.Now method
DateTime dt1 = System.DateTime.Now;
System.Threading.Thread.Sleep(time_cap);
DateTime dt2 = System.DateTime.Now;

TimeSpan ts = dt2.Subtract(dt1);
Console.WriteLine("example1 time {0}", ts.TotalMilliseconds);

System.Diagnostics.Stopwatch stopwatch = new Stopwatch();
stopwatch.Start(); //  开始监视代码运行时间
//  需要测试的代码 ....
stopwatch.Stop(); //  停止监视
TimeSpan timespan = stopwatch.Elapsed; //  获取当前实例测量得出的总时间
double hours = timespan.TotalHours; // 总小时
double minutes = timespan.TotalMinutes;  // 总分钟
double seconds = timespan.TotalSeconds;  //  总秒数
double milliseconds = timespan.TotalMilliseconds;  //  总毫秒数