c# 计算程序执行时间,计算一段代码执行所用的时间,测试效率

using System;
using System.Threading;
class Class1
{
[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);
[STAThread]
static void Main(string[] args)
{
long count = 0;
long count1 = 0;
long freq = 0;
double result = 0;
QueryPerformanceFrequency(ref freq);
QueryPerformanceCounter(ref count);
//需要测试的模块

int heisetoufa;
for (heisetoufa = 1; heisetoufa < 10000; heisetoufa++)
{
Console.WriteLine("第" + heisetoufa + "行");
if (heisetoufa == 5000)
{
Thread.Sleep(10000);
}
}

//需要测试的模块

QueryPerformanceCounter(ref count1);
count = count1 - count;
result = (double)(count) / (double)freq;
Console.WriteLine("耗时: {0} 秒", result);
Console.ReadLine();
}
}