C# 时间

private DateTime StampToDateTime(string timeStamp)
{
DateTime dateTimeStart = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1));
long lTime = long.Parse(timeStamp + "0000000");
TimeSpan toNow = new TimeSpan(lTime);
return dateTimeStart.Add(toNow);
}

private int DateTimeToStamp(System.DateTime time)
{
System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new         System.DateTime(1970, 1, 1));
return (int)(time - startTime).TotalSeconds;
}

DateTime.Now.ToString();            // 2008-9-4 20:02:10
DateTime.Now.ToLocalTime().ToString();        // 2008-9-4 20:12:12

DateTime.Now.ToLongDateString().ToString();    // 2008年9月4日
DateTime.Now.ToShortDateString().ToString();    // 2008-9-4
DateTime.Now.ToString("yyyy-MM-dd");        // 2008-09-04
DateTime.Now.Date.ToString();            // 2008-9-4 0:00:00

DateTime.Now.ToLongTimeString().ToString();   // 20:16:16
DateTime.Now.ToShortTimeString().ToString();   // 20:16
DateTime.Now.ToString("hh:mm:ss");        // 08:05:57
DateTime.Now.TimeOfDay.ToString();        // 20:33:50.7187500

DateTime.ToFileTime().ToString();       // 128650040212500000
DateTime.Now.ToFileTimeUtc().ToString();   // 128650040772968750
DateTime.Now.ToOADate().ToString();       // 39695.8461709606
DateTime.Now.ToUniversalTime().ToString();   // 2008-9-4 12:19:14

DateTime.Now.Year.ToString();          获取年份   // 2008
DateTime.Now.Month.ToString();      获取月份   // 9
DateTime.Now.DayOfWeek.ToString(); 获取星期   // Thursday
DateTime.Now.DayOfYear.ToString(); 获取第几天   // 248
DateTime.Now.Hour.ToString();          获取小时   // 20
DateTime.Now.Minute.ToString();     获取分钟   // 31
DateTime.Now.Second.ToString();     获取秒数   // 45

dt.AddYears(n).ToString();   //时间加n年
dt.AddDays(n).ToString();   //加n天
dt.AddHours(n).ToString();   //加n小时
dt.AddMonths(n).ToString();   //加n个月
dt.AddSeconds(n).ToString();   //加n秒
dt.AddMinutes(n).ToString();   //加n分