static void SubTest()

{

    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);

}

第一种方法利用System.DateTime.Now

static void SubTest()

{

    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);

}