//Main方法，测试方法运行正常using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ObserverClock{    class Program    {        static void Main(string[] args)        {            UtcTime utcTime = new UtcTime();            utcTime.attach("北京", new CityClock(8));            utcTime.attach("伦敦", new CityClock(0));            utcTime.attach("墨西哥", new CityClock(4));            utcTime.attach("悉尼", new CityClock(10));            utcTime.attach("纽约", new CityClock(-5));            PhoneClock phoneClock = new PhoneClock(8);            phoneClock.setUtcTime(utcTime);            phoneClock.setLocalTime(9);            utcTime.showAllClocks();            Console.ReadLine();        }    }}//UtcTime,用于设置时区时间和显示时区时间using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ObserverClock{    public class UtcTime : TimeSubject    {        private int uctZeroTime;               public int UctZeroTime        {            get { return uctZeroTime; }            set {                 uctZeroTime = value;                notifyAllClocks();            }        }                      public override void notifyAllClocks()        {            foreach (Clock clock in base.clocks.Values)            {                clock.setLocalTimeFromUtcZeroTime(this.uctZeroTime);            }        }        public void showAllClocks()        {             foreach (string CityName in base.clocks.Keys)            {                Console.WriteLine(CityName + ":" + base.clocks[CityName].localTime);            }        }    }}//PhoneClock，Clock的继承者，用于设置手机时间，从而将所有时区的时间设置using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ObserverClock{    public class PhoneClock : Clock    {        public PhoneClock(int utcOffset)            : base(utcOffset)        {        }        private UtcTime utcTime;        public override void setLocalTime(int localTime)        {            base.localTime = localTime;            utcTime.UctZeroTime = localTime - UTC_OFFSET;        }        public void setUtcTime(UtcTime _utcTime)        {            utcTime = _utcTime;        }    }}//CityClock，Clock的继承者，用于设置对应的时区时间using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ObserverClock{    public class CityClock : Clock    {        public CityClock( int utcOffset): base(utcOffset)        {                  }        public override void setLocalTime(int localTime)        {            base.localTime = localTime;        }    }}//Clock类，被观察者using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ObserverClock{    //抽象类    public abstract class Clock    {        public Clock()        {         }        public int UTC_OFFSET = 0;              public int localTime = 0;        public Clock(int utcOffset)        {            UTC_OFFSET = utcOffset;        }        public abstract void setLocalTime(int localTime);        public void setLocalTimeFromUtcZeroTime(int utcZeroTime)        {            this.localTime = Clock.MakeHourWithin0To23(utcZeroTime + this.UTC_OFFSET);        }        private static int MakeHourWithin0To23(int hour)        {            return (hour + 24) % 24;        }    }}//TimeSubject类，观察者，用于添加和移除被观察者using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ObserverClock{    public abstract class TimeSubject    {        protected Dictionary
     
       clocks = new Dictionary
      
       ();        public void attach(string cityName, Clock clock)        {            clocks.Add(cityName, clock);        }        public void detach(string cityName, Clock clock)        {            clocks.Remove(cityName);        }        public abstract void notifyAllClocks();    }}