设计模式之 中介者模式

当多个类之间需要建立联系时，为了避免多个类之间的耦合，通过一个“中介者”类专门负责多个类之间的信息交换。

现有婚姻介绍所为例：韩梅梅和李雷（有车有房，年龄稍大）都在婚介所注册了会员，韩梅梅在听了婚介所工作人员对李雷的介绍后决定约李雷见面，于是婚介所工作人员将话带到了李雷那里。代码如下：

中介抽象类：

abstract class Mediator
    {
        public abstract void Register(People people);
       
        public abstract void SetMessage(string message, People from, string to);
    }

继承了中介抽象类具体的婚介所类：

 class MatrimonialMediator:Mediator
    {
        private List<People> _list = new List<People>();

        public override void Register(People people)
        {
            _list.Add(people);
        }

        public override void SetMessage(string message, People from, string to)
        {
            Console.WriteLine("{0}通过中介对{1}说:{2}", from.Name, to, message);

            foreach (var item in _list)
            {
                if (item.Name == to)
                {
                    item.RecevieMessage(message,from.Name);
                    break;
                }
            }
        }
    }

会员基类：

 abstract class People
    {
        private  string _name;
        private  Mediator _mediator;

        public Mediator Mediator
        {
            get { return _mediator; }
        }

        public string Name
        {
            get { return _name; }
        }

        public People(string name, Mediator mediator)
        {
            _name = name;
            _mediator = mediator;
            _mediator.Register(this);
        }

        public abstract void SetMessage(string message,string to);
        public abstract void RecevieMessage(string message,string from);
    }

继承了会员基类的男人类：

class Man:People
    {
        public Man(string name,Mediator mediator)
            : base(name, mediator)
        {

        }

        public override void SetMessage(string message,string to)
        {
            this.Mediator.SetMessage(message, this, to);
        }
        public override void RecevieMessage(string message, string from)
        {
            Console.WriteLine(string.Format("{0}（男）收到了{1}的消息：{2}", this.Name, from, message));
        }
    }

继承了会员基类的女人类：

 class Woman:People
    {
        public Woman(string name, Mediator mediator)
            : base(name, mediator)
        {

        }
        public override void SetMessage(string message, string to)
        {
            this.Mediator.SetMessage(message, this, to);
        }

        public override void RecevieMessage(string message, string from)
        {
            Console.WriteLine("{0}（女）收到了{1}的消息：{2}");
        }
    }

测试代码如下：

 static void Main(string[] args)
        {
            MatrimonialMediator matrimonialMediator = new MatrimonialMediator();
            People HanMeimei = new Woman("韩美美", matrimonialMediator);
            People LiLei = new Man("李雷", matrimonialMediator);

            HanMeimei.SetMessage("约在XXXX见面", "李雷");
            Console.Read();
        }

运行结果：

看了有戏！！