C++ 时间获取和时间测量

1，计算使用多长时间

tick精度：

LARGE_INTEGER frequency;        // ticks per second
LARGE_INTEGER t1, t2;           // ticks
double elapsedTime;

// get ticks per second
QueryPerformanceFrequency(&frequency);

// start timer
QueryPerformanceCounter(&t1);

// do something
...

// stop timer
QueryPerformanceCounter(&t2);

// compute and print the elapsed time in millisec
elapsedTime = (t2.QuadPart - t1.QuadPart) * 1000.0 / frequency.QuadPart;

　　

（毫秒级）：

clock_t start = clock();

double elapsedTime = 0;
Sleep(1000);

clock_t end = clock();

elapsedTime = (end - start) / CLOCKS_PER_SEC;//1000/1000

　　

秒级精度：

CTime CurrentTime = CTime::GetCurrentTime();
Sleep(100);
CTime CurrentTime2 = CTime::GetCurrentTime();
CTimeSpan ts = CurrentTime2 - CurrentTime;