C#计算一段程序运行时间的三种方法

亲测有效~

 

直接代码：
第一种方法利用System.DateTime.Now

 

        public static void SubTest()
        {
            DateTime beforeDT = System.DateTime.Now;
            int[] a = new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 };
            //Shuffle(a) is the function you want to test.
            Shuffle(a);
            DateTime afterDT = System.DateTime.Now;
            TimeSpan ts = afterDT.Subtract(beforeDT);
            Console.WriteLine("DateTime costed for Shuffle function is: {0}ms",ts.TotalMilliseconds);
        }

第二种用Stopwatch类(System.Diagnostics)

        public static void SubTest()
        {
            Stopwatch sw = new Stopwatch();
            sw.Start();
            //Shuffle(a) is the function you want to test.
            int[] a = new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 };
            Shuffle(a);
            sw.Stop();
            TimeSpan ts = sw.Elapsed;
            Console.WriteLine("DateTime costed for Shuffle function is: {0}ms", ts.TotalMilliseconds);
        }

第三种用API实现：个人感觉以秒为单位来计算程序耗时，数量级有点大了，还是推荐前面两种毫秒级别的……

        [System.Runtime.InteropServices.DllImport("Kernel32.dll")]
        static extern bool QueryPerformanceCounter(ref long count);
        [System.Runtime.InteropServices.DllImport("Kernel32.dll")]
        static extern bool QueryPerformanceFrequency(ref long count);  
        public static void SubTest()
        {
            long count = 0;
            long count1 = 0;
            long freq = 0;
            double result = 0;
            QueryPerformanceFrequency(ref freq);
            QueryPerformanceCounter(ref count);
            //Shuffle(a) is the function you want to test.
            int[] a = new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 };
            Shuffle(a);
            QueryPerformanceCounter(ref count1);
            count = count1 - count;
            result = (double)(count) / (double)freq;
            //Note:The result is counted by second.
            Console.WriteLine("DateTime costed for Shuffle function is: {0} s", result);
        }

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作者：传说中的汽水枪
来源：CSDN
原文：https://blog.csdn.net/xzjxylophone/article/details/6832160
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