C#计算一段程序运行时间的三种方法-优快云博客

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); 
          
           }

第二种用Stopwatch类(System.Diagnostics)：

 
           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); 
          
           }

第三种用API实现：

 
           [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); 
          
           static 
           void 
           SubTest() 
          
           {
          
           long 
           count = 0; 
          
           long 
           count1 = 0; 
          
           long 
           freq = 0; 
          
           double 
           result = 0; 
          
           QueryPerformanceFrequency(
           ref 
           freq); 
          
           QueryPerformanceCounter(
           ref 
           count); 
          
           //耗时巨大的代码
          
           QueryPerformanceCounter(
           ref 
           count1); 
          
           count = count1 - count;
          
           result = (
           double
           )(count) / (
           double
           )freq; 
          
           Console.WriteLine(
           "QueryPerformanceCounter耗时: {0} 秒"
           , result); 
          
           }