Asp.net 时间操作基类(短日期,长日期,时间差)

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

namespace EC
...{
    /**//// <summary>
    /// 时间操作函数
    /// </summary>
    public class TimeObject
    ...{
        /**//// <summary>
        /// 时间差
        /// </summary>
        /// <param name="starttime">开始时间</param>
        /// <param name="endtime">结束时间</param>
        /// <returns></returns>
        public static string GetTimeSpan(DateTime starttime, DateTime endtime)
        ...{
            TimeSpan ts = endtime - starttime;
            return string.Format("{0}时{1}分{2}秒{3}毫秒", ts.Hours, ts.Minutes, ts.Seconds, ts.Milliseconds);
        }

        /**//// <summary>
        /// 转称为月-日:09-12
        /// </summary>
        /// <param name="d">日期</param>
        /// <returns></returns>
        public static string ToDateMonthDay(DateTime d)
        ...{
            return d.ToString("MM-dd");
        }
        /**//// <summary>
        /// 转换为年月日:2006-09-12
        /// </summary>
        /// <param name="d"></param>
        /// <returns></returns>
        public static string ToDateString(DateTime d)
        ...{
            return d.ToString("yyyy-MM-dd");
        }
        /**//// <summary>
        /// 转换为:小时:分:秒 00:29:58
        /// </summary>
        /// <param name="t"></param>
        /// <returns></returns>
        public static string ToTimeString(DateTime t)
        ...{
            return t.ToString("HH:mm:ss");
        }
        /**//// <summary>
        /// 转换为长时间:2006-09-12 00:30:57
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></returns>
        public static string ToDateTimeString(DateTime dt)
        ...{
            return dt.ToString("yyyy-MM-dd HH:mm:ss");
        }     

    
    }

}