C#之时间统计

DateTime beforDT = System.DateTime.Now;

    //耗时巨大的代码

    DateTime afterDT = System.DateTime.Now;
    TimeSpan ts = afterDT.Subtract(beforDT);
    Console.WriteLine("DateTime总共花费{0}ms.", ts.TotalMilliseconds);

 Stopwatch sw = new Stopwatch();
    sw.Start();

    //耗时巨大的代码

    sw.Stop();
    TimeSpan ts2 = sw.Elapsed;
    Console.WriteLine("Stopwatch总共花费{0}ms.", ts2.TotalMilliseconds);