基于事件委托多线程实现的时钟

发布者：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace clock
{
    class Clock//public使其可被继承，发布者类
    {
        private int _hour;
        private int _minute;
        private int _second;
        public delegate void SecondChangeHandler(object clock,TimeInfoEventArgs timeInformation,int outdata);//可自定义的委托代理

        public event SecondChangeHandler SecondChange;//定义事件，事件封装委托，成为事件类型的委托。多数类已有的定义

        protected void OnSecondChange(object clock, TimeInfoEventArgs timeInformation) {//定义触发事件
            if (SecondChange != null) {//事件已被订阅
                SecondChange(clock,timeInformation,1);//通过事件执行委托方法
            }
        }

        public void Run() {//在一定的条件下触发事件
            for (;;) {

                Thread.Sleep(1000);
                System.DateTime dt = System.DateTime.Now;
                if (dt.Second != _second) {
                    TimeInfoEventArgs timeInformation = new TimeInfoEventArgs(dt.Hour,dt.Minute,dt.Second);
                    OnSecondChange(this,timeInformation);
                }
                _second = dt.Second;
                _minute = dt.Minute;
                _hour = dt.Hour;
            }
        }
    }

    public class TimeInfoEventArgs
    {
        public readonly int hour;
        public readonly int minute;
        public readonly int second;

        public TimeInfoEventArgs(int hour, int minute, int second)
        {
            this.hour = hour;
            this.minute = minute;
            this.second = second;
        }
    }
}

订阅者（观察者模式）：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace clock
{
    class DisplayClock//观察者类（订阅者）
    {
        public void Subscribe(Clock theClock) {
            theClock.SecondChange += new Clock.SecondChangeHandler(TimeHasChange);//通过委托代理将自定义方法注册到类的事件，订阅事件，即先将方法关联到委托，再将委托注册到事件
        }

        private void TimeHasChange(object clock, TimeInfoEventArgs timeInformation,int outdata)//订阅事件后自生成事件处理函数来响应事件
        {
            //throw new NotImplementedException();
            Console.WriteLine("current time:{0}:{1}:{2}", timeInformation.hour.ToString(),
                timeInformation.minute.ToString(),
                timeInformation.second.ToString());
        }
    }
    class LogClock {
        public void Subscribe(Clock theClock)
        {
            theClock.SecondChange += new Clock.SecondChangeHandler(WriteLogentry);
            theClock.SecondChange += new Clock.SecondChangeHandler(showclocl);
        }

        private void showclocl(object clock, TimeInfoEventArgs timeInformation, int outdata)
        {
            Console.WriteLine("show time:{0}:{1}:{2}", timeInformation.hour.ToString(),
                timeInformation.minute.ToString(),
                timeInformation.second.ToString());
            //throw new NotImplementedException();
        }

        private void WriteLogentry(object clock, TimeInfoEventArgs timeInformation,int outdata)
        {
            //throw new NotImplementedException();
            Console.WriteLine("Logging to file:{0}:{1}:{2}",timeInformation.hour.ToString(),
                timeInformation.minute.ToString(),
                timeInformation.second.ToString());
        }
    }
}