C# TimeSpan获取 年月

   public static string GetYearMonthDayString(this DateTime expires)
        {
            try
            {

                var now = DateTime.Now;
                TimeSpan ts = expires - now;
                int year = , month = , day = ts.Days;

                year = (int)ts.TotalDays / ;
                DateTime mi = now.AddYears(year);
                while ((mi = mi.AddMonths()) <= expires)
                {
                    month++;
                }
                if (year >  && month <= )
                {
                    return $"{year}年";
                }
                if (year >  && month > )
                {
                    return $"大约{year}年{month}个月";
                }

                if (year <=  && month > )
                {
                    return $"大约{month}个月";
                }
                if (year <=  && month <= &&day>)
                {
                    return $"{day}天";
                }
                if (year <=  && month <=  && day <= &&ts.Hours>)
                {
                    return $"{ts.Hours}小时";

                }
                return $"{Convert.ToInt16(ts.Days <= 0?0:ts.Days)}天";
            }
            catch
            {

            }
            return "";
        }