时间段划分

网上找过很多给一个时间段划分的功能，但是都感觉不是特别全也不是特别好用，索性自己根据网上的资料参考自己写了一个。

可以根据星期、月份、季度、年划分时间段（是严格按照起止时间划分的，例如：开始时间      2020-12-31     结束时间     2021-3-5，按月份划分就是  2020年12月份、2021年1月份、2021年2月份、2021年3月份；季度和年也是如此，后续可以根据自己需要改动代码）。

废话少说，直接上代码

public static class DateSplitHelper
    {
        #region 根据周期类型获取时间段分组 杨福良 2021-4-15 10:25:12
        /// <summary>
        /// 根据周期类型获取时间段分组
        /// </summary>
        /// <param name="startDate"></param>
        /// <param name="endDate"></param>
        /// <param name="caredCycle"></param>
        /// <returns></returns>
        public static Dictionary<string, string> GetDates(DateTime startDate, DateTime endDate, int caredCycle)
        {
            Dictionary<string, string> dates = new Dictionary<string, string>();
            if (caredCycle == 0)
            {
                dates = DateSplitHelper.GetGroupWeek(startDate.ToShortDateString(), endDate.ToShortDateString());
                return dates;
            }
            if (caredCycle == 1)
            {
                dates = DateSplitHelper.GetGroupMonth(startDate.ToShortDateString(), endDate.ToShortDateString());
                return dates;
            }
            if (caredCycle == 2)
            {
                dates = DateSplitHelper.GetGroupSeason(startDate.ToShortDateString(), endDate.ToShortDateString());
                return dates;
            }
            if (caredCycle == 3)
            {
                dates = DateSplitHelper.GetGroupYear(startDate.ToShortDateString(), endDate.ToShortDateString());
                return dates;
            }
            return dates;
        }
        #endregion

        #region 根据时间范围获取每周分组 杨福良 2021-4-14 21:49:46
        /// <summary>
        /// 根据时间范围获取每周分组
        /// </summary>
        /// <param name="strStartDate">起始时间</param>
        /// <param name="strEndDate">结束时间</param>
        /// <returns>返回每周起始结束键值对</returns>
        
        
        static DateTime LastDayOfMonth(DateTime datetime)
        {
            return datetime.AddDays(1 - datetime.Day).AddMonths(1).AddDays(-1);
        }
        #endregion

        #region 获取当前季度 杨福良 2021-4-25 18:02:44
        /// <summary>
        /// 获取当前季度
        /// </summary>
        /// <param name="date"></param>
        /// <returns></returns>
        public static string GetMonthSeason(this string date)
        {
            DateTime dt = Convert.ToDateTime(date);
            int month = dt.Month;
            if (month <= 3)
            {
                return $"{dt.Year}年1季度";
            }
            if (month <= 6 && month >= 4)
            {
                return $"{dt.Year}年2季度";
            }
            if (month <= 9 && month >= 7)
            {
                return $"{dt.Year}年3季度";
            }
            return $"{dt.Year}年4季度";
        }
        #endregion

        /// <summary>
        /// 日期转换
        /// </summary>
        /// <param name="date"></param>
        /// <param name="caredCycle">统计周期 0 按周 1 按月 2 按季度 3 按年</param>
        /// <returns></returns>
        public static string DateTransform(string startDate, string endDate, int caredCycle)
        {
            StringBuilder strSql = new StringBuilder();
            if (caredCycle == 0)
            {
                strSql.Append($@" 
                        '{startDate}-{endDate}'AS AreaSection,   ");
            }
            if (caredCycle == 1)
            {
                strSql.Append($@"
                        '{Convert.ToDateTime(startDate).GetDateTimeFormats('y')[0].ToString()}'AS AreaSection,");
            }
            if (caredCycle == 2)
            {
                strSql.Append($@"
                        '{startDate.GetMonthSeason()}'AS AreaSection,");
            }
            if (caredCycle == 3)
            {
                strSql.Append($@"
                        '{Convert.ToDateTime(startDate).Year}年'AS AreaSection,");
            }
            return strSql.ToString();
        }

        static Dictionary<string, string> GetGroupWeek(string strStartDate, string strEndDate)
        {
            DateTime dtStartDate = DateTime.Parse(strStartDate);
            DateTime dtEndDate = DateTime.Parse(strEndDate);
            Dictionary<string, string> dict = new Dictionary<string, string>();

            bool ok = true;
            while (ok)
            {
                DayOfWeek day = dtStartDate.DayOfWeek;
                string dayString = day.ToString();
                DateTime dtTempStartDate = dtStartDate;
                DateTime dtTempDate = DateTime.Now;
                switch (dayString)
                {
                    case "Monday":
                        dtTempDate = dtTempStartDate.Date.AddDays(+6);
                        break;
                    case "Tuesday":
                        dtTempDate = dtTempStartDate.Date.AddDays(+5);
                        break;
                    case "Wednesday":
                        dtTempDate = dtTempStartDate.Date.AddDays(+4);
                        break;
                    case "Thursday":
                        dtTempDate = dtTempStartDate.Date.AddDays(+3);
                        break;
                    case "Friday":
                        dtTempDate = dtTempStartDate.Date.AddDays(+2);
                        break;
                    case "Saturday":
                        dtTempDate = dtTempStartDate.Date.AddDays(+1);
                        break;
                    case "Sunday":
                        dtTempDate = dtTempStartDate;
                        break;
                }
                if (dtTempDate > dtEndDate)
                {
                    dict.Add(dtTempStartDate.ToString(), dtEndDate.ToString());
                    ok = false;
                    continue;
                }
                dict.Add(dtTempStartDate.ToString(), dtTempDate.ToString());
                dtStartDate = dtTempDate.Date.AddDays(+1);
                if (dtStartDate > dtEndDate)
                {
                    ok = false;
                }
            }

            return dict;
        }

        static Dictionary<string, string> GetGroupMonth(string strStartDate, string strEndDate)
        {
            DateTime dtStartDate = DateTime.Parse(strStartDate);
            DateTime dtEndDate = DateTime.Parse(strEndDate);
            Dictionary<string, string> dict = new Dictionary<string, string>();

            bool ok = true;
            while (ok)
            {
                DateTime dtTempStartDate = dtStartDate;
                DateTime dtTempDate = LastDayOfMonth(dtStartDate);
                if (dtTempDate > dtEndDate)
                {
                    dtTempDate = dtEndDate;
                    ok = false;
                }
                dict.Add(dtTempStartDate.ToString(), dtTempDate.ToString());
                dtStartDate = dtTempDate.Date.AddDays(+1);
                if (dtStartDate > dtEndDate)
                    ok = false;
                //if (dtTempDate > dtEndDate)
                //{
                //    dict.Add(dtTempStartDate.ToString(), dtEndDate.ToString());
                //    ok = false;
                //    continue;
                //}
                //dict.Add(dtTempStartDate.ToString(), dtTempDate.ToString());
                //dtStartDate = dtTempDate.Date.AddDays(+1);
            }
            return dict;
        }

        static Dictionary<string, string> GetGroupSeason(string strStartDate, string strEndDate)
        {
            DateTime dtStartDate = DateTime.Parse(strStartDate);
            DateTime dtEndDate = DateTime.Parse(strEndDate);
            DateTime dtTempStartDate = dtStartDate;
            DateTime dtTempDate = DateTime.Now;
            Dictionary<string, string> dict = new Dictionary<string, string>();
            bool ok = true;
            while (ok)
            {
                int currentMonth = dtStartDate.Month;
                int currentSeason = currentMonth / 3 + (currentMonth % 3 > 0 ? 1 : 0);
                dtTempDate = DateTime.Parse(DateTime.Parse(dtStartDate.Year + "." + (currentSeason * 3) + "." + "01").ToString("yyyy.MM.dd"));
                dtTempDate = LastDayOfMonth(dtTempDate);
                if (dtTempDate > dtEndDate)
                {
                    dtTempDate = dtEndDate;
                    ok = false;
                }
                dict.Add(dtTempStartDate.ToString(), dtTempDate.ToString());
                dtStartDate = dtTempDate.Date.AddDays(+1);
                if (dtStartDate > dtEndDate)
                {
                    dtTempDate = dtEndDate;
                    ok = false;
                }
                dtTempStartDate = dtTempDate.Date.AddDays(+1);
            }
            return dict;
        }
        static Dictionary<string, string> GetGroupYear(string strStartDate, string strEndDate)
        {
            Dictionary<string, string> dict = new Dictionary<string, string>();

            DateTime dtStartDate = DateTime.Parse(strStartDate);
            DateTime dtEndDate = DateTime.Parse(strEndDate);

            //同年
            if (dtStartDate.Year == dtEndDate.Year)
            {
                dict.Add(dtStartDate.ToShortDateString(), new DateTime(dtStartDate.Year + 1, 1, 1).AddDays(-1).ToShortDateString());
                return dict;
            }
            bool ok = true;
            while (ok)
            {
                DateTime dtTempStartDate = dtStartDate;
                DateTime dtTempDate = DateTime.Parse(DateTime.Parse(dtStartDate.Year + ".12." + "31").ToString("yyyy.MM.dd"));
                if (dtTempDate > dtEndDate)
                {
                    dtTempDate = dtEndDate;
                    ok = false;
                }
                dict.Add(dtTempStartDate.ToString(), dtTempDate.ToString());
                dtStartDate = dtTempDate.Date.AddDays(+1);
                if (dtStartDate > dtEndDate)
                {
                    dtTempDate = dtEndDate;
                    ok = false;
                }
            }
            return dict;
        }
    }

大家有疑问的地方可以随时沟通，非常乐意哦~~~