毫秒计数转化为std::tm以及SYSTEM

#include <windows.h>
#include <chrono>
#include <ctime>
#include <iostream>

using namespace std;

LONGLONG GetCurTime()
{
	return std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
}

int main()
{
	INT64 milli = GetCurTime() + (INT64)8 * 60 * 60 * 1000;//此处转化为东八区北京时间，如果是其它时区需要按需求修改
	auto mTime = std::chrono::milliseconds(milli);
	auto tp = std::chrono::time_point<std::chrono::system_clock, std::chrono::milliseconds>(mTime);
	auto tt = std::chrono::system_clock::to_time_t(tp);
	std::tm* now = std::gmtime(&tt);
	printf("%4d年%02d月%02d日 %02d:%02d:%02d\n", now->tm_year + 1900, now->tm_mon + 1, now->tm_mday, now->tm_hour, now->tm_min, now->tm_sec);
	
    //struct tm结构和struct SYSTEMTIME结构的年和月的取值范围是不一样的 :
    //tm.tm_mon = systemtime.wMonth - 1
    //tm.tm_year = systemtime.wYear - 1900
    SYSTEMTIME st;
	st.wYear = now->tm_year + 1900;
	st.wMonth = now->tm_mon + 1;
	st.wDayOfWeek = now->tm_wday;
	st.wDay = now->tm_mday;
	st.wHour = now->tm_hour;
	st.wMinute = now->tm_min;
	st.wSecond = now->tm_sec;
	st.wMilliseconds = 0;

    while (1);
	return 0;
}