设计模式学习笔记——中介者模式（Mediator）

1.特点：由中介封装一系列对象交互，减少对象间耦合，利于复用。（朋友多）

2.概念：定义一个中介对象来封装系列对象之间的交互。

3.类图：

4.程序实现：

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

namespace Mediator
{
    class Program
    {
        static void Main(string[] args)
        {
            ConcreteMediator m = new ConcreteMediator();
            ConcreteColleague1 c1 = new ConcreteColleague1(m);
            ConcreteColleague2 c2 = new ConcreteColleague2(m);
            m.Colleague1 = c1;
            m.Colleague2 = c2;

            c1.Send("你吃过了么");
            c2.Send("没有呢，你请客？");

            Console.Read();
        }
    }
    abstract class Mediator
    {
        public abstract void Send(string message, Colleague colleague);
    }
    //抽象同事类
    abstract class Colleague
    {
        protected Mediator mediator;
        public Colleague(Mediator mediator)
        {
            this.mediator = mediator;
        }
    }

    class ConcreteMediator : Mediator
    {
        private ConcreteColleague1 colleague1;
        private ConcreteColleague2 colleague2;

        public ConcreteColleague1 Colleague1
        {
            set { this.colleague1 = value; }
        }

        public ConcreteColleague2 Colleague2
        {
            set { this.colleague2 = value; }
        }

        public override void Send(string message, Colleague colleague)
        {
            if (colleague == colleague1)
            {
                colleague2.Notify(message);
            }
            else
            {
                colleague1.Notify(message);
            }
        }
    }

    class ConcreteColleague1 : Colleague
    {
        public ConcreteColleague1(Mediator mediator)
            : base(mediator)
        {

        }

        public void Send(string message)
        {
            mediator.Send(message, this);
        }
        public void Notify(string message)
        {
            Console.WriteLine("同事1得到消息：" + message);
        }
    }

    class ConcreteColleague2 : Colleague
    {
        public ConcreteColleague2(Mediator mediator)
            : base(mediator)
        {

        }

        public void Send(string message)
        {
            mediator.Send(message, this);
        }
        public void Notify(string message)
        {
            Console.WriteLine("同事2得到消息：" + message);
        }
    }
}