如何將std :: chrono :: high_resolution_clock :: now（）轉換爲Windows文件時間（和反向轉換）

Question

是否有方法將std :: chrono :: high_resolution_clock :: now（）時間輕鬆轉換爲Windows文件時間（https://msdn.microsoft.com/en-us/library/windows/desktop/ms724284(v=vs.85).aspx）（和後面）？我不知道如何處理這個...

非常感謝！

Answer 1

您可以將time_point轉換爲time_t，然後使用以下函數將其轉換爲FILETIME。

std::time_t t; 
t = to_time_t(std::chrono::high_resolution_clock::now()); 

然後轉換爲FILETIME（https://msdn.microsoft.com/en-us/library/windows/desktop/ms724228%28v=vs.85%29.aspx）

#include <windows.h> 
#include <time.h> 

void TimetToFileTime(time_t t, LPFILETIME pft) 
{ 
    LONGLONG ll = Int32x32To64(t, 10000000) + 116444736000000000; 
    pft->dwLowDateTime = (DWORD) ll; 
    pft->dwHighDateTime = ll >>32; 
} 

此外，請記住在Windows上high_resolution_clock被實現爲不那麼高清晰度system_clock

Answer 2

這似乎是正確的解決方案：

FILETIME fileTime = { 0 }; 
long long timePointTmp = std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::high_resolution_clock::now().time_since_epoch()).count() * 10 + 116444736000000000; 
fileTime.dwLowDateTime = (unsigned long)timePointTmp; 
fileTime.dwHighDateTime = timePointTmp >> 32;