c# DateTime常用操作实例(datetime计算时间差)

#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