中介者模式:用一个中介对象来封装一系列的对象交互。中介者使各对象不需要显式的相互引用,从而使得其耦合松散,而且可以独立的改变它们之间的交互。

 abstract class Mediator//抽象中介者
    {
        public abstract void Send(string message, Colleague colleague);
    }
    abstract class Colleague//抽象同事类
    {
        protected Mediator mediator;
        public Colleague(Mediator mediator)
        {
            this.mediator = mediator;
        }
    }
    class ContreteMediater:Mediator//具体中介类
    {
        private ContreteColleague1 colleague1;
        private ContreteColleague2 colleague2;
        public ContreteColleague1 Colleague1
        {
            set { colleague1 = value; }
        }
        public ContreteColleague2 Colleague2
        {
            set { colleague2 = value; }
        }
        public override void Send(string message, Colleague colleague)
        {
            if (colleague == colleague1)
                colleague2.Notify(message);
            else if (colleague == colleague2)
                colleague1.Notify(message);
        }
    }
    class ContreteColleague1:Colleague、、
    {
        public ContreteColleague1(Mediator mediator):base(mediator)
        { }
        public void Send(string message)
        {
            mediator.Send(message, this);
        }
        public void Notify(string message)
        {
            Console.WriteLine("colleage1 get messgae " + message);
        }
    }
    class ContreteColleague2 : Colleague//具体同事类2
    {
        public ContreteColleague2(Mediator mediator) : base(mediator)
        { }
        public void Send(string message)
        {
            mediator.Send(message, this);
        }
        public void Notify(string message)
        {
            Console.WriteLine("colleage2 get messgae " + message);
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            ContreteMediater m = new ContreteMediater();
            ContreteColleague1 c1 = new ContreteColleague1(m);
            ContreteColleague2 c2 = new ContreteColleague2(m);
            m.Colleague1 = c1;
            m.Colleague2 = c2;
            c1.Send("nice to meet you ");
            c2.Send("nice to meet you too");
            Console.Read();
        }
    }
中介者一般应用于一组对象以定义良好但是复杂的方式进行通信的场合,以及向定制分布在多个类中的行为,而又不想生成太多子类