MyDateTime

     定义名为MyTime的类其中应有三个整型成员时hour分minute秒second为了保证数据的安全性这三个成员变量应声明为私有。 
     为MyTime类定义构造方法以方便创建对象时初始化成员变量。 
     再定义diaplay方法用于将时间信息打印出来。 
     为MyTime类添加以下方法 
    * addSecond(int sec) 
    * addMinute(int min) 
    * addHour(int hou) 
    * subSecond(int sec) 
    * subMinute(int min) 
    * subHour(int hou) 
    * 分别对时、分、秒进行加减运算。

namespace _0703_面向对象
{
    class MyTime
    {
        private int _hour;
        private int _minute;
        private int _second;
        public int Hour
        {
            get { return _hour; }
            set { _hour = value; }
        }
        public int Minute
        {
            get { return _minute; }
            set { _minute = value; }
        }
        public int Second
        {
            get { return _second; }
            set { _second = value; }
        }
        public MyTime(int h, int m, int s)
        {
            Hour = h;
            Minute = m;
            Second = s;
        }
        public void Display()//展示时间
        {
            Console.WriteLine("{0}时{1}分{2}秒", Hour, Minute, Second);
        }

        public void  AddHour(int h)
        {
            Hour = Hour + h;
            Test();
        }
        public void AddMinute(int m)
        {
            Minute += m;
            Test();
        }
        public void  AddSecond(int s)
        {
            Second += s;
            Test();

        }
        public void  SubHour(int h)
        {
            Hour -= h;
            Test();
        }
        public void SubMinute(int m)
        {
            Minute -= m;
            Test();
        }
        public void SubSecond(int s)
        {
            Second -= s;
            Test();
        }

        public void Test() {
            //判断秒
            if (Second >= 60) {
                Minute += Second / 60;
                Second = Second % 60;
            } else if (Second < 0) {
                Minute += (Second / 60 - 1);
                Second = Second % 60 + 60;
            }
            //判断分
            if (Minute >= 60) {
                Hour += Minute / 60;
                Minute =Minute % 60;
            } else if (Minute < 0) {
                Hour += (Minute / 60 - 1);
                Minute = Minute % 60 + 60;
            }
            //判断时
            if (Hour > 24) {
                Hour = Hour % 24; 
            }if (Hour < 0)
            {
                Hour = Hour % 24 + 24; 
            }
        }
    }
}