# 中介者模式

属于行为型模式。
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。

适用性：

网络聊天室是一个很好的例子。

# 类图

	namespace BehavioralPatterns_MediatorPattern
	{
	/// <summary>
	/// 玩家
	/// </summary>
	public abstract class Player
	{
	/// <summary>
	/// 中介者
	/// </summary>
	protected Mediator MainMediator;

	public Player(Mediator mainMediator)
	{
	MainMediator = mainMediator;
	}

	/// <summary>
	/// 发送消息
	/// </summary>
	/// <param name="target"> 目标 & lt;/param>
	/// <param name="message"> 消息内容 & lt;/param>
	public abstract void Send(string target, string message);

	/// <summary>
	/// 接收消息
	/// </summary>
	/// <param name="sender"> 发送者 & lt;/param>
	/// <param name="message"> 消息内容 & lt;/param>
	public virtual void Receive(string sender, string message)
	{
	Console.WriteLine(sender + ": " + message);
	}
	}
	}

	namespace BehavioralPatterns_MediatorPattern
	{
	public class PlayerA : Player
	{
	public PlayerA(Mediator mainMediator) : base(mainMediator)
	{
	MainMediator.PlayerDic.Add("PlayerA", this);
	}

	public override void Send(string target, string message)
	{
	MainMediator.SendMediator("PlayerA", target, message);
	}
	}
	}

	namespace BehavioralPatterns_MediatorPattern
	{
	public class PlayerB : Player
	{
	public PlayerB(Mediator mainMediator) : base(mainMediator)
	{
	MainMediator.PlayerDic.Add("PlayerB", this);
	}

	public override void Send(string target, string message)
	{
	MainMediator.SendMediator("PlayerB", target, message);
	}
	}
	}

	namespace BehavioralPatterns_MediatorPattern
	{
	/// <summary>
	/// 中介者
	/// </summary>
	public class Mediator
	{
	/// <summary>
	/// 储存所有的对象
	/// </summary>
	public Dictionary<string, Player> PlayerDic;

	public Mediator()
	{
	PlayerDic = new Dictionary<string, Player>();
	}

	/// <summary>
	/// 发送消息的中介
	/// </summary>
	/// <param name="sender"> 发送者 & lt;/param>
	/// <param name="target"> 目标 & lt;/param>
	/// <param name="message"> 消息内容 & lt;/param>
	public void SendMediator(string sender, string target, string message)
	{
	PlayerDic[target].Receive(sender, message);
	}
	}
	}

	namespace BehavioralPatterns_MediatorPattern
	{
	public class Program
	{
	private static void Main()
	{
	Mediator mediator = new Mediator();

	Player playerA = new PlayerA(mediator);
	Player playerB = new PlayerB(mediator);

	playerA.Send("PlayerB", "playerA_message");
	}
	}
	}

运行结果：
PlayerA: playerA_message