VC中监测程序运行时间（二）-毫秒级

 /*
 *    微秒级计时器，用来统计程序运行时间
 *   http://blog.csdn.net/hoya5121/article/details/3778487#comments
 *   //整理 [10/16/2013 Duan Yihao]
 */

 #pragma once

 #include "stdafx.h"

 //////////////////////////////////////////////////////////////////////////
 class timer
 {
 public:
     timer();
     ~timer();

     void start(void);

     void end(void);   

     DWORD getTime(void) const;

 private:
     LARGE_INTEGER m_i64CPUFreq;
     LARGE_INTEGER m_i64Begin;
     LARGE_INTEGER m_i64End;
     void reset(void);
 };

 //////////////////////////////////////////////////////////////////////////
 timer::timer()
 {
     QueryPerformanceFrequency(&m_i64CPUFreq);
 }

 timer::~timer()
 {

 }

 void timer::start(void)
 {
     reset();
     QueryPerformanceCounter(&m_i64Begin);
 }

 void timer::end(void)
 {
     QueryPerformanceCounter(&m_i64End);
 }

 DWORD timer::getTime(void) const
 {
     DWORD dwTotalMicrosecond = ;
     LARGE_INTEGER i64TickCount;
     i64TickCount.QuadPart = m_i64End.QuadPart - m_i64Begin.QuadPart;
     dwTotalMicrosecond = (DWORD) (i64TickCount.QuadPart *  / m_i64CPUFreq.QuadPart);

     return dwTotalMicrosecond;
 }

 void timer::reset(void)
 {
     m_i64Begin = m_i64End;
 }

 /*
 //////////////////////////////////////////////////////////////////////////
 //MFC下使用举例：

 void CtestMFCView::OnTest()
 {

     // TODO: 在此添加命令处理程序代码
     //测试例子

     //计时开始
     timer t;
     t.start();

     //运算过程

         for(int i = 0; i < 10; i++)
         {
             int n = i;
             for(int i = 0; i < 10000; i++)
             {
                 int n = i;
             }
         }

     //计时结束
     t.end();

     //输出运行时间
     CString s;
     s.Format(_T("%u ms"), t.getTime());
     AfxMessageBox(s);
 }

 */