#region DateTime操作     public class C3     {         //DateTime常用的操作         public static void Fun1()         {             //格式：2012-8-16 11:21:29             Console.WriteLine("当前时间：{0}", DateTime.Now.ToString());             //格式：2012-8-16 0:00:00             Console.WriteLine("日期部分：{0}", DateTime.Now.Date.ToString());             //格式：11:21:29             Console.WriteLine("时间部分：{0}", DateTime.Now.ToLongTimeString());             //获取此实例的当天的时间。相当的精确【到毫秒】             Console.WriteLine("TimeOfDay:{0}", DateTime.Now.TimeOfDay.ToString());             Console.WriteLine("取中文日期显示_年月日时分:{0}", DateTime.Now.ToString("f"));             Console.WriteLine("取中文日期显示_年月:{0}", DateTime.Now.ToString("y"));             Console.WriteLine("取中文日期显示_月日:{0}", DateTime.Now.ToString("m"));             Console.WriteLine("取中文年月日:{0}", DateTime.Now.ToString("D"));             //取当前时分，格式为：14：24             Console.WriteLine("取当前时分:{0}", DateTime.Now.ToString("t"));             //取当前时间，格式为：2003-09-23T14:46:48             Console.WriteLine("取当前时分:{0}", DateTime.Now.ToString("s"));             //取当前时间，格式为：2003-09-23 14:48:30Z             Console.WriteLine("取当前时分:{0}", DateTime.Now.ToString("u"));             //取当前时间，格式为：2003-09-23 14:48             Console.WriteLine("取当前时分:{0}", DateTime.Now.ToString("g"));             //取当前时间，格式为：Tue, 23 Sep 2003 14:52:40 GMT             Console.WriteLine("取当前时分:{0}", DateTime.Now.ToString("r"));             //获得当前时间 n 天后的日期时间             DateTime newDay = DateTime.Now.AddDays(100);             Console.WriteLine(newDay.ToString());             Console.WriteLine("年：{0}", DateTime.Now.Year.ToString());             Console.WriteLine("月：{0}", DateTime.Now.Month.ToString());             Console.WriteLine("日：{0}", DateTime.Now.Day.ToString());             Console.WriteLine("时：{0}", DateTime.Now.Hour.ToString());             Console.WriteLine("分：{0}", DateTime.Now.Minute.ToString());             Console.WriteLine("秒：{0}", DateTime.Now.Second.ToString());             Console.WriteLine("毫秒：{0}", DateTime.Now.Millisecond.ToString());             Console.WriteLine("计时周期数：{0}", DateTime.Now.Ticks.ToString());             Console.WriteLine("星期：{0}", DateTime.Now.DayOfWeek.ToString());             Console.WriteLine("一年中的第几天：{0}", DateTime.Now.DayOfYear.ToString());         }         //客户端代码         public static void MyFun()         {             //struct本身是一个结构体             //DateTime dt0 = new DateTime();             DateTime dt1 = new DateTime(2012, 8, 14, 10, 54, 55);             DateTime dt2 = new DateTime(2012, 12, 21);//2012-12-21 00:00:00             Console.WriteLine(DateDiff(dt1, dt2));             //我活了多少天了             DateTime dt3 = new DateTime(2012, 8, 14, 12, 00, 00);             DateTime dt4 = new DateTime(1990, 11, 17, 02, 48, 00);//2012-12-21 00:00:00             Console.WriteLine("我活了多少天" + DateDiff(dt4, dt3));         }         //计算时间的差值         public static string DateDiff(DateTime DateTime1, DateTime DateTime2)         {             string dateDiff = null;             TimeSpan ts1 = new TimeSpan(DateTime1.Ticks);             TimeSpan ts2 = new TimeSpan(DateTime2.Ticks);             TimeSpan ts = ts1.Subtract(ts2).Duration();             dateDiff = ts.Days.ToString() + "天" + ts.Hours.ToString() + "小时" + ts.Minutes.ToString() + "分钟" + ts.Seconds.ToString() + "秒";             return dateDiff;             #region note             //C#中使用TimeSpan计算两个时间的差值             //可以反加两个日期之间任何一个时间单位。             //TimeSpan ts = Date1 - Date2;             //double dDays = ts.TotalDays;//带小数的天数，比如1天12小时结果就是1.5             //int nDays = ts.Days;//整数天数，1天12小时或者1天20小时结果都是1              #endregion         }     }     #endregion