C# 常用日期相关处理方法整理-木庄网络博客

        #region 日期

        /// <summary>
        /// 格式化日期类型，返回字符串
        /// </summary>
        /// <param name="dtime">日期</param>
        /// <param name="s">日期年月日间隔符号</param>
        /// <returns></returns>
		public static String Fomatdate(DateTime dtime,String s)
		{
			String datestr="";
			datestr=dtime.Year.ToString() + s + dtime.Month.ToString().PadLeft(2,'0')+ s +dtime.Day.ToString().PadLeft(2,'0');
			return datestr;
		}

        /// <summary>
        /// 返回日期差
        /// </summary>
        /// <param name="sdmin">开始日期</param>
        /// <param name="sdmax">结束日期</param>
        /// <returns>日期差：负数为失败</returns>
		public static int Datediff(DateTime sdmin,DateTime sdmax)
		{
			try
			{
				double i=0;
				while(sdmin.AddDays(i)<sdmax)
				{
					i++;
				}
				return Utility.ToInt(i);
			}
			catch
			{
			    return -1;
			}
		}

        /// <summary>
        /// 返回日期差
        /// </summary>
        /// <param name="sdmin">开始日期</param>
        /// <param name="sdmax">结束日期</param>
        /// <returns>日期差：负数为失败</returns>
		public static int Datediff(String sdmin,String sdmax)
		{
			try
			{
				DateTime dmin;
				DateTime dmax;
				dmin=DateTime.Parse(sdmin);
				dmax=DateTime.Parse(sdmax);
				double i=0;
				while(dmin.AddDays(i)<dmax)
				{
					i++;
				}
				return Utility.ToInt(i);
			}
			catch
			{
			    return -1;
			}
		}

		#endregion