中介者模式

定义：用一个中介对象来封装一系列的对象交互，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。多个对象可以互相通信，建立一个中间的中介类完成彼此间的通信，类似于QQ功能，链接多个类似的对象。

优点：

1、降低了类的复杂度，将一对多转化成了一对一。

2、各个类之间的解耦。

3、符合迪米特原则。

使用前：

使用后：

缺点：中介者会庞大，变得复杂难以维护。

实现：以下案例建立一个类似于QQ的功能。单个对象通过QQMeditor于其他对象通信。

1.创建单个的对象的抽象类和实现类：

public abstract class Colleage
{
    private string _name;
    private string _content;
    public Colleage(string n) { _name = n; }
    public string Name
    {
        get {  return _name;}
        set { _name = value; }
    }

    public string Content
    {
        get { return _content;}
        set{  _content = value; }
    }
    public virtual void Talk(){}
}

public class ColleageA : Colleage
{
    public ColleageA(string name): base(name){ }
    public override void Talk()
    {
        base.Talk();
        Debug.Log("ColleageA说: " + Content);
    }
}   
                                                                           
public class ColleageB : Colleage
{
    public ColleageB(string name) : base(name) { }
    public override void Talk()
    {
        base.Talk();
        Debug.Log("ColleageB说: " + Content);
    }
}

public class ColleageC : Colleage
{
    public ColleageC(string name) : base(name) { }
    public override void Talk()
    {
        base.Talk();
        Debug.Log("ColleageC说: " + Content);
    }
}

2.创建中介类的抽象类和实现类：

public abstract class Meaditor
{
    protected List<Colleage> Colleages = new List<Colleage>();
    public virtual void AddColleage(Colleage c){}
    public virtual void RemoveColleage(Colleage c){}
    public  virtual void Notify(Colleage student){}
    public virtual void Chart(Colleage A, Colleage B){}
}

public class QQMeaditor:Meaditor
{
    public override void AddColleage(Colleage c)
    {
        Colleages.Add(c);
    }

    public override void RemoveColleage(Colleage c)
    {
        Colleages.Remove(c);
    }

    public override void Notify(Colleage student)
    {
        int count = Colleages.Count;
        for (int i = 0; i < count; i++)
        {
            Colleages[i].Talk();
        }
    }

    public override void Chart(Colleage A, Colleage B)
    {
        A.Talk();
        B.Talk();
    }
}

3.创建客户端类，实现具体调用：

public class Client:MonoBehaviour
{  
    void Start()
    {
    //创建单个对象和中介对象QQ
        QQMeditor qq = new QQMeditor();
        ColleageA a = new ColleageA("A");
        ColleageB b = new ColleageB("B");
        ColleageB c = new ColleageB("C");

        a.Content = "加油！";
        b.Content = "-----";
        c.Content = "=====";
    //添加多个对象进管理数组

        qq.AddColleage(a);
        qq.AddColleage(b);
        qq.AddColleage(c);

        qq.Notify(a);
        b.Content = "_________";
        c.Content = "+++++++++";
        qq.Chart(b, c);
    }
}