c#关于时间TimeHelper类的总结

namespace DotNet.Utilities
{
    /// <summary>
    /// 时间类
    /// 1、SecondToMinute(int Second) 把秒转换成分钟
    /// </summary>
    public class TimeHelper
    {
        /// <summary>
        /// 将时间格式化成 年月日 的形式,如果时间为null，返回当前系统时间
        /// </summary>
        /// <param>年月日分隔符</param>
        /// <param></param>
        /// <returns></returns>
        public string GetFormatDate(DateTime dt, char Separator)
        {
            if (dt != null && !dt.Equals(DBNull.Value))
            {
                string tem = string.Format("yyyy{0}MM{1}dd", Separator, Separator);
                return dt.ToString(tem);
            }
            else
            {
                return GetFormatDate(DateTime.Now, Separator);
            }
        }
        /// <summary>
        /// 将时间格式化成 时分秒 的形式,如果时间为null，，返回当前系统时间
        /// </summary>
        /// <param></param>
        /// <param></param>
        /// <returns></returns>
        public string GetFormatTime(DateTime dt, char Separator) {
            if (dt != null && !dt.Equals(DBNull.Value))
            {
                string tem = string.Format("hh{0}mm{1}ss", Separator, Separator);
                return dt.ToString(tem);
            }
            else
            {
                return GetFormatDate(DateTime.Now, Separator);
            }
        }
        /// <summary>
        /// 把秒转换成分钟
        /// </summary>
        /// <returns></returns>
        public static int SecondToMinute(int Second)
        {
            decimal mm = (decimal)((decimal)Second / (decimal)60);
            return Convert.ToInt32(Math.Ceiling(mm));
        }

#region 返回某年某月最后一天
        /// <summary>
        /// 返回某年某月最后一天
        /// </summary>
        /// <param>年份</param>
        /// <param>月份</param>
        /// <returns>日</returns>
        public static int GetMonthLastDate(int year, int month)
        {
            DateTime lastDay = new DateTime(year, month, new System.Globalization.GregorianCalendar().GetDaysInMonth(year, month));
            int Day = lastDay.Day;
            return Day;
        }
        #endregion