Winapi 获取两个SYSTEMTIME变量之间的差

例如，我的代码如下

void main()

{

       SYSTEMTIME LocalTime_Start = { 0 };

        GetLocalTime( &LocalTime_Start );

        SYSTEMTIME LocalTime_End = { 0 };
        // Some program Statements

         GetLocalTime( &LocalTime_End );

         // Now i want difference of two i.e.
         // can i do as following
         SYSTEMTIME localTime_diff = LocalTime_End - LocalTime_Start;
         // guys please let me know how to achieve that asap...thanks a lot in advance
}

---

使用将两个SYSTEMTIME结构转换为FILETIME

FILTETIME ft;
::SystemTimeToFileTime(&sysTime, &ft);

使用以下命令将FILETIME转换为ULONGLONG：

ULARGE_INTEGER uli;
uli.LowPart = ft.dwLowDateTime ;
uli.HighPart= ft.dwHighDateTime;
ULONGLONG uft= uli.QuadPart;

---

减去ULONGLONGs得到以Hectonanosc为单位的时间差

在这种情况下不适用，但如果输入SYSTEMTIME表示零时间（即其所有成员均为0），SystemTimeToFileTime将失败。