取得两个 FILETIME 的时间差

如果为SYSTEMTIME，可以通过SystemTimeToFileTime先转到FILETIME

#define NOMINMAX

#include <algorithm>
#include <windows.h>

SYSTEMTIME systemtime_difference(SYSTEMTIME const& st1, SYSTEMTIME const& st2)
{
    FILETIME ft1;
    SystemTimeToFileTime(&st1, &ft1);
    ULARGE_INTEGER const u1 = { ft1.dwLowDateTime, ft1.dwHighDateTime };

    FILETIME ft2;
    SystemTimeToFileTime(&st2, &ft2);
    ULARGE_INTEGER const u2 = { ft2.dwLowDateTime, ft2.dwHighDateTime };

    ULARGE_INTEGER u3;
    u3.QuadPart = std::max(u1.QuadPart, u2.QuadPart) - std::min(u1.QuadPart, u2.QuadPart);
    FILETIME const ft3 = { u3.LowPart, u3.HighPart };

    SYSTEMTIME st3;
    FileTimeToSystemTime(&ft3, &st3);
    // FILETIME's starting point is 1601-01-01
    st3.wYear -= 1601;
    st3.wMonth -= 1;
    st3.wDay -= 1;
    st3.wDayOfWeek = 0; // useless for this purpose, make it always 0 so it's always ignored
    return st3;
}

int main()
{
    SYSTEMTIME const st1 = { 2008, 10, 3, 15, 6, 5, 31, 12 };
    SYSTEMTIME const st2 = { 2009, 12, 0, 27, 10, 7, 59, 56 };
    SYSTEMTIME st3 = systemtime_difference(st1, st2);

    return 0;
}

#define NOMINMAX 

#include <algorithm> 
#include <windows.h> 
 
SYSTEMTIME systemtime_difference(SYSTEMTIME const& st1, SYSTEMTIME const& st2) 
{ 
    FILETIME ft1; 
    SystemTimeToFileTime(&st1, &ft1); 
    ULARGE_INTEGER const u1 = { ft1.dwLowDateTime, ft1.dwHighDateTime }; 
 
    FILETIME ft2; 
    SystemTimeToFileTime(&st2, &ft2); 
    ULARGE_INTEGER const u2 = { ft2.dwLowDateTime, ft2.dwHighDateTime }; 
 
    ULARGE_INTEGER u3; 
    u3.QuadPart = std::max(u1.QuadPart, u2.QuadPart) - std::min(u1.QuadPart, u2.QuadPart); 
    FILETIME const ft3 = { u3.LowPart, u3.HighPart }; 
 
    SYSTEMTIME st3; 
    FileTimeToSystemTime(&ft3, &st3); 
    // FILETIME's starting point is 1601-01-01 
    st3.wYear -= 1601; 
    st3.wMonth -= 1; 
    st3.wDay -= 1; 
    st3.wDayOfWeek = 0; // useless for this purpose, make it always 0 so it's always ignored 
    return st3; 
} 
 
int main() 
{ 
    SYSTEMTIME const st1 = { 2008, 10, 3, 15, 6, 5, 31, 12 }; 
    SYSTEMTIME const st2 = { 2009, 12, 0, 27, 10, 7, 59, 56 }; 
    SYSTEMTIME st3 = systemtime_difference(st1, st2); 
 
    return 0; 
} 

 

感谢：http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/fe975619-5e19-45e0-82cd-797ff7745712