ASP.NET日期操作常用代码

using System;

namespace My.Utils {
 /// <summary>
 /// 日期操作常用工具
 /// </summary>
 public class DateUtils {
  public DateUtils() {
  }

        /// <summary>
        /// 比较日期的年份差
        /// </summary>
        /// <param name="start">开始日期</param>
        /// <returns>与当前日期的年份差</returns>
        public static int DiffYear (string start) {
            return DiffYear(Convert.ToDateTime(start));
        }

        /// <summary>
        /// 比较日期的年份差
        /// </summary>
        /// <param name="start">开始日期</param>
        /// <param name="end">结束日期</param>
        /// <returns>年份差</returns>
        public static int DiffYear (string start, string end) {
            return DiffYear(Convert.ToDateTime(start), Convert.ToDateTime(end));
        }
       
        /// <summary>
        /// 比较日期的年份差
        /// </summary>
        /// <param name="start">开始日期</param>
        /// <returns>与当前日期的年份差</returns>
        public static int DiffYear (DateTime start) {
            return (DiffYear(start, DateTime.Now));
        }

        /// <summary>
        /// 比较两个日期的年份差
        /// </summary>
        /// <param name="start">开始日期</param>
        /// <param name="end">结束日期</param>
        /// <returns>年份差</returns>
        public static int DiffYear (DateTime start, DateTime end) {
            return (end.Year - start.Year);
        }

        /// <summary>
        /// 格式化当天日期(yyyy-MM-dd)
        /// </summary>
        /// <returns>格式化后的日期字符串</returns>
        public static string DateFormat () {
            return DateFormat(DateTime.Now);
        }

        /// <summary>
        /// 格式化日期(yyyy-MM-dd)
        /// </summary>
        /// <param name="date">待格式化的日期</param>
        /// <returns>格式化后的日期字符串</returns>
        public static string DateFormat (string date) {
            return DateFormat(Convert.ToDateTime(date));
        }

        /// <summary>
        /// 格式化日期
        /// </summary>
        /// <param name="date">待格式化的日期</param>
        /// <param name="format">格式化串</param>
        /// <returns>格式化后的日期字符串</returns>
        public static string DateFormat (string date, string format) {
            return DateFormat(Convert.ToDateTime(date), format);
        }

        /// <summary>
        /// 格式化日期(yyyy-MM-dd)
        /// </summary>
        /// <param name="date">待格式化的日期</param>
        /// <returns>格式化后的日期字符串</returns>
        public static string DateFormat (DateTime date) {
            return DateFormat(date, "yyyy-MM-dd");
        }

        /// <summary>
        /// 格式化日期
        /// </summary>
        /// <param name="date">待格式化的日期</param>
        /// <param name="format">格式化串</param>
        /// <returns>格式化后的日期字符串</returns>
        public static string DateFormat (DateTime date, string format) {
            return date.ToString(format);
        }

        /// <summary>
        /// 格式化日期时间
        /// </summary>
        /// <param name="datetime">待格式化的日期时间</param>
        /// <returns>格式化后的日期时间字符串</returns>
        public static string DateTimeFormat (DateTime datetime) {
            return DateTimeFormat(datetime, "yyyy-MM-dd HH:mm");
        }

        /// <summary>
        /// 格式化日期时间
        /// </summary>
        /// <param name="datetime">待格式化的日期时间</param>
        /// <param name="format">格式化串</param>
        /// <returns>格式化后的日期时间字符串</returns>
        public static string DateTimeFormat (DateTime datetime, string format) {
            return datetime.ToString(format);
        }
 }
}