事件的应用

    class PubEventArgs : EventArgs
    {
        private readonly string m_name;
        private readonly DateTime m_date;
        public PubEventArgs (string name,DateTime date )
        {
            m_name=name ;
            m_date = date;
        }
        public string name
        {
            get 
            {
                return m_name;
            }
        }
        public DateTime  date
        {
            get
            {
                return m_date;
            }
        }

    }
    class Publisher   //发行方
    {
        public delegate void PubComputerEventHandler(object sender, PubEventArgs e);   //定义委托
        public delegate void PubLifeEvertHandler(object sender, PubEventArgs e);       //定义委托
        public event PubComputerEventHandler pubcomputer;       //定义事件      格式：【访问修饰符】 + event + 委托 +事件名
        public event PubLifeEvertHandler publife;               //定义事件
        public virtual void OnComputer(PubEventArgs e)   
        {
            PubComputerEventHandler handler = pubcomputer;　　　//声明临时委托
            if (handler != null)
            {
                handler(this,e );
            }
        }
        public virtual void OnLife(PubEventArgs e)
        {
            PubLifeEvertHandler handler = publife;
            if(handler !=null )
            {
                handler(this, e);
            }
        }
        public void IstureComputer(string name, DateTime date)  //触发电脑杂志事件
        {
            Console.WriteLine("发行" + name);
            OnComputer(new PubEventArgs (name,date )); 
        }
        public void IstrueLife(string name, DateTime date)    //触发生活杂志事件
        {
            Console.WriteLine("发行" + name);
            OnLife(new PubEventArgs(name, date));
        }

    }
    class Reader    //订阅事件
    {
        private string name;
        public Reader(string name)
        {
            this.name = name;
        }
        public void Receive(object sender, PubEventArgs e)  //必须和委托参数一样
        {
            Console.WriteLine(e.date + "已收到" + name + e.name);
        }
    }
    class Test
    {
        static void Main()
        {
            Publisher aa = new Publisher();
            Reader zs = new Reader("张三");
            //订阅事件   格式：事件名+=new 委托名（）
            aa.pubcomputer += new Publisher.PubComputerEventHandler(zs.Receive);   //触发事件
            Reader ls = new Reader("李四");
            aa.pubcomputer += new Publisher.PubComputerEventHandler(ls.Receive);  //触发事件
            aa.publife += new Publisher.PubLifeEvertHandler(ls.Receive);          //触发事件
            aa.IstureComputer ("电脑杂志" , Convert.ToDateTime("2005-08-18"));
         
            aa.IstrueLife("生活杂志" , Convert.ToDateTime("2005-08-18"));


        }
    }