C# 精準計時之 QueryPerformanceCounter QueryPerformanceFrequency用法

標籤：

C# 用法：

    public static class QueryPerformanceMethd    {        [DllImport("kernel32.dll")]      public  extern static short QueryPerformanceCounter(ref long x);        [DllImport("kernel32.dll")]        public extern static short QueryPerformanceFrequency(ref long x);    }

 

    static void Main(string[] args)        {            long stop_Value = 0;            long start_Value = 0;            long freq = 0;            QueryPerformanceMethd.QueryPerformanceFrequency(ref freq);            QueryPerformanceMethd.QueryPerformanceCounter(ref start_Value);            //Fun()    需要計時方法                      QueryPerformanceMethd.QueryPerformanceCounter(ref stop_Value);            double time = (double)(stop_Value - start_Value) / (double)(freq);            Console.WriteLine(time);//單位S            Console.ReadLine();        }    

計算所得time即為fun（）方法所消耗時間。

 

 

C++中QueryPerformanceCounter  QueryPerformanceFrequency的用法

#include "stdafx.h"#include "windows.h"void main(){    LARGE_INTEGER nFreq;    LARGE_INTEGER nBeginTime;    LARGE_INTEGER nEndTime;    double time;    QueryPerformanceFrequency(&nFreq);    QueryPerformanceCounter(&nBeginTime);    Sleep(1000);    QueryPerformanceCounter(&nEndTime);    time = (double)(nEndTime.QuadPart - nBeginTime.QuadPart) / (double)nFreq.QuadPart;    printf("%f\n", time);    system("Pause");}

計算Sleep（1000）所消耗的精確時間，並非精確的1s

 

C# 精準計時之 QueryPerformanceCounter QueryPerformanceFrequency用法