时间格式数据及字符串的简单处理

#include "stdafx.h"
/// 判断文件格式
const unsigned int GetFileFormat(TCHAR* sFileName)
{
	unsigned int iRet = E_FileERR;

	/// 0、判断文件名是否有效
	//if (sFileName.IsEmpty() || 4 > sFileName.GetLength())
	//	return iRet;
	int iLenth = WideCharToMultiByte(CP_ACP, 0, sFileName, -1, NULL, 0, NULL, NULL);
	if (iLenth == 0 || 4 > iLenth)
		return iRet;

	string strFileName = C22<255>(sFileName);
	size_t iLen = strFileName.length();
	int iPos = strFileName.find_last_of(‘.‘);
	if (iPos >= 0 && iPos < iLen)
	{
		string strSuff(strFileName.substr(iPos, iLen - iPos));
		/// 转变为小写，方便比较扩展名
		transform(strSuff.begin(), strSuff.end(), strSuff.begin(), tolower);

		if (!(strSuff.compare(".csv")))
		{
			iRet = E_FileCSV;
		}
		else if (!(strSuff.compare(".txt")))
		{
			iRet = E_FileTXT;
		}
		else if (!(strSuff.compare(".xls")))
		{
			iRet = E_FileXLS;
		}
		else if (!(strSuff.compare(".xlsx")))
		{
			iRet = E_FileXLSX;
		}
		else if (!(strSuff.compare(".dbf")))
		{
			iRet = E_FileDBF;
		}

	}

	return iRet;
}

const SYSTEMTIME Time_tToSystemTime(time_t t)
{
	tm temptm;
	localtime_s(&temptm, &t);
	SYSTEMTIME st = { 1900 + temptm.tm_year,
		1 + temptm.tm_mon,
		temptm.tm_wday,
		temptm.tm_mday,
		temptm.tm_hour,
		temptm.tm_min,
		temptm.tm_sec,
		0 };
	return st;
}

const time_t SystemTimeToTime_t(const SYSTEMTIME& st)
{
	struct tm gm = { st.wSecond, st.wMinute, st.wHour, st.wDay, st.wMonth - 1, st.wYear - 1900, st.wDayOfWeek, 0, 0 };
	return mktime(&gm);
}

const SYSTEMTIME GetTimeFromString(std::string szTime, std::string szGap, bool bOneDayTime)
{
	SYSTEMTIME targetTime = { 0 };
	int gapSize = szTime.find(szGap);
	int pos0 = szTime.find_first_of(szGap);
	int pos1 = szTime.find_last_of(szGap);
	if (pos0 < 0 || pos1 < 0 || pos0 == pos1)
	{
		return targetTime;
	}
	string szHead(szTime.c_str(), pos0);
	string szMiddle(szTime.c_str() + pos0 + 1, pos1 - pos0 - 1);
	string szTail(szTime.c_str() + pos1 + 1, szTime.length() - pos1 - 1);

	if (bOneDayTime) //HH:mm:ss
	{
		targetTime = { 0, 0, 0, 0, atoi(szHead.c_str()), atoi(szMiddle.c_str()), atoi(szTail.c_str()), 0 };
	}
	else			//YYYY:MM:DD
	{
		targetTime = { atoi(szHead.c_str()), atoi(szMiddle.c_str()), 0, atoi(szTail.c_str()), 0, 0, 0, 0 };
	}
	return targetTime;
}

//获取指定月份天数(//改为获取当月最后一个工作日)
const unsigned int GetDaysInMonth(const unsigned int year, const unsigned int month)
{
	unsigned int tmpDay;
	const int day[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
	if (month == 2)
	{
		tmpDay = ((0 == year % 4) && (0 != year % 100) || (0 == year % 400)) ? 29 : 28;
	}
	else if (month > 12)
	{
		tmpDay = 30;
	}
	else
	{
		tmpDay = day[month - 1];
	}
	return tmpDay;
}

//获取当前时间点当月最后一个工作日
const SYSTEMTIME GetCurMonthLastWorkDay(SYSTEMTIME curTime)
{
	unsigned int lastDay = GetDaysInMonth(curTime.wYear, curTime.wMonth);
	time_t lastDaySecond = SystemTimeToTime_t(curTime) + (lastDay - curTime.wDay) * (24 * 3600);
	SYSTEMTIME lastDayTime = Time_tToSystemTime(lastDaySecond);
	return GetLastWorkDay(lastDayTime);
}

//获取当前时间点最后一个工作日的日期
const SYSTEMTIME GetLastWorkDay(const SYSTEMTIME& st)
{
	int endSeconds = 0;
	if (0 == st.wDayOfWeek % 6)
	{
		time_t selTime_t = SystemTimeToTime_t(st);
		//当前时间点为周末
		if (st.wDayOfWeek == 6)
		{
			endSeconds = (24 * 3600) * 1;
		}
		else
		{
			endSeconds = (24 * 3600) * 2;
		}

		return  Time_tToSystemTime(selTime_t - endSeconds);
	}
	else
	{
		//当前时间点为工作日
		return st;
	}
}

//获取当前时间点包含N个工作日的起始日期(默认是5个工作日)
const SYSTEMTIME GetFirstWorkDay(const SYSTEMTIME& st, const unsigned int nDaysBefor)
{
	int startSecond = 0;
	int endSeconds = 0;
	time_t selTime_t = SystemTimeToTime_t(st);
	//获取日期前推
	if (st.wDayOfWeek % 6 == 0)//当日为周末
	{

		if (st.wDayOfWeek == 6)
		{
			endSeconds = (24 * 3600) * 1;
		}
		else
		{
			endSeconds = (24 * 3600) * 2;
		}
		int nAddDay = nDaysBefor % 5 == 0 ? -1 : 0;
		startSecond = (24 * 3600) * (nDaysBefor - 1) + (48 * 3600) * (nDaysBefor / 5 + nAddDay) + endSeconds;
	}
	else						//当日即为工作日
	{
		if (st.wDayOfWeek > nDaysBefor)
		{
			startSecond = (24 * 3600) * (nDaysBefor - 1);
		}
		else
		{
			int nAddDay = (nDaysBefor - st.wDayOfWeek) % 5 == 0 ? 0 : 1;
			startSecond = (24 * 3600) * (nDaysBefor - 1) + (48 * 3600) * ((nDaysBefor - st.wDayOfWeek) / 5 + nAddDay);
		}
	}

	return Time_tToSystemTime(selTime_t - startSecond);		//第一个工作日
}

static int IsLeapYear(int year)
{
	if ((year % 4 == 0) && (year % 100 != 0) || year % 400 == 0)
		return 366;
	else
		return 365;
}

const SYSTEMTIME GetFirstWorkDayOfOneYear(const WORD nYear)
{
	int nTotalDays = 0;
	for (int i = 1; i < nYear; i++)
		nTotalDays += IsLeapYear(i);
	int nDayOfWeek = (nTotalDays + 1) % 7;
	int nStartDay = 1;
	int nSetDayOfWeek = nDayOfWeek;
	if (nDayOfWeek == 6)
	{
		nSetDayOfWeek = 1;
		nStartDay += 2;
	}
	else if (nDayOfWeek == 0)
	{
		nSetDayOfWeek = 1;
		nStartDay += 1;
	}
	SYSTEMTIME firstWorkDay = { nYear, 1, nSetDayOfWeek, nStartDay, 0, 0, 0, 0 };
	return firstWorkDay;
}

const string GetFutureCode(SYSTEMTIME sysTm, E_FUTURECODE eType, E_FUTURETIME eMonth)
{
	string szStr;
	if (eType == TYPE_IFCODE)
	{
		szStr = "IF";
	}
	else if (eType == TYPE_IHCODE)
	{
		szStr = "IH";
	}
	else
	{
		szStr = "IC";
	}
	char szTime[5];
	memset(szTime, 0, sizeof(szTime));
	//CURMONTH
	int year = sysTm.wYear % 100;
	int month = sysTm.wMonth;
	bool bNext = false;

	//判断当月第1天是一周的第几天
	int gapDay;
	time_t selTime = SystemTimeToTime_t(sysTm);
	SYSTEMTIME time_fir = Time_tToSystemTime(selTime - (sysTm.wDay - 1)  * 24 * 3600);
	//如果第1天不是第一周日期
	if (time_fir.wDayOfWeek % 6 == 0)			//周末
	{
		gapDay = 1 + (5 + time_fir.wDayOfWeek / 6) + 14;
	}
	else //第一天为周五
	{
		gapDay = 1 + (5 - time_fir.wDayOfWeek) + 14;
	}
	if (sysTm.wDay > gapDay)
	{
		if (month == 12)
		{
			month = 1;
			year += 1;
		}
		else
		{
			month += 1;
		}
	}

	if (eMonth == TIME_NEXTMONTH || bNext)
	{
		if (month == 12)
		{
			month = 1;
			year += 1;
		}
		else
		{
			month += 1;
		}
	}
	else if (eMonth == TIME_ENDOFSEASON)
	{
		month += 3 - month % 3;
		if (month > 12)
		{
			year += 1;
			month %= 12;
		}
	}
	else if (eMonth == TIME_NEXTENDOFSEASON)
	{
		if (month % 3 == 0)
		{
			month += 6;
		}
		if (month > 12)
		{
			year += 1;
			month %= 12;
		}
	}
	sprintf_s(szTime, "%02d%02d", year, month);
	szStr.append(szTime);
	return szStr;
}

原文地址：https://www.cnblogs.com/depend-wind/p/9638546.html