设计模式-中介者模式

用来降低多个对象和类之间的通信复杂性。这种模式提供了一个中介类，该类通常处理不同类之间的通信，并支持松耦合，使代码易于维护
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地相互引用，从而使其耦合松散，而且可以独立地改变它们之间的交互
对象与对象之间存在大量的关联关系，这样势必会导致系统的结构变得很复杂，同时若一个对象发生改变，我们也需要跟踪与之相关联的对象，同时做出相应的处理

中介者模式

//Mediator 抽象中介者
abstract class Mediator
{
    public abstract void Send(string message, Colleague colleague);
}
//Colleague 抽象同事类
abstract class Colleague
{
    protected Mediator mediator;
    public Colleague(Mediator mediator)
    {
        this.mediator = mediator;
    }
}
class ConcreateMediator : Mediator
{
    private ConcreateColleague1 colleague1;
    private ConcreateColleague2 colleague2;
    public ConcreateColleague1 Colleague1
    {
        set{colleague1 = value;}
    }
    public ConcreateColleague2 Colleague2
    {
        set{colleague2 = value;}
    }
    public override void Send(string message, Colleague colleague)
    {
        if(colleague == colleague1)
            colleague2.Notify(message)
        else
            colleague1.Notify(message);
    }
}
class ConcreateColleague1 : Colleague
{
    public ConcreateColleague1(Mediator mediator) : base(mediator)
    {}
    public void Send(string message)
    {
        mediator.Send(message, this);
    }
    public void Notify(string message)
    {
        Console.WriteLine("Colleague 1 Recv " + message);
    }
}
class ConcreateColleague2 : Colleague
{
    public ConcreateColleague2(Mediator mediator) : base(mediator)
    {}
    public void Send(string message)
    {
        mediator.Send(message, this);
    }
    public void Notify(string message)
    {
        Console.WriteLine("Colleague 2 Recv " + message);
    }
}
//Client
ConcreateMediator m = new ConcreateMediator();//创建中介
ConcreateColleague1 c1 = new ConcreateColleague1(m);//让同事都认识中介
ConcreateColleague2 c2 = new ConcreateColleague2(m);

m.colleague1 = c1;//让中介认识同事
m.colleague2 = c2;

c1.Send("你瞅啥");
c2.Send("瞅你咋地");