unity 事件（委托）

头段时间做NGUI的时候，老大给我优化了很多，用到了C#的事件。由于我之前不是学C#的，下来花了点时间看了一下事件。我老大主要把事件用于对UI界面的切换。下面我们来看看代码吧。我的例子很简单的。

EventManager.cs  

using System;
using System.Collections.Generic;
 
public class EventArgs
{
 
}
 
public class EventManager
{
    static EventManager _instance;
    public static EventManager Instance
    {
        get
        {
            if (_instance == null)
            {
                _instance = new EventManager();
            }
 
            return _instance;
        }
    }
 
    public delegate void EventDelegate<T>(T e) where T : EventArgs;
 
    readonly Dictionary<Type, Delegate> _delegates = new Dictionary<Type, Delegate>();
 
    public void AddListener<T>(EventDelegate<T> listener) where T : EventArgs
    {
        Delegate d;
        if (_delegates.TryGetValue(typeof(T), out d))
        {
            _delegates[typeof(T)] = Delegate.Combine(d, listener);
        }
        else
        {
            _delegates[typeof(T)] = listener;
        }
    }
 
    public void RemoveListener<T>(EventDelegate<T> listener) where T : EventArgs
    {
        Delegate d;
        if (_delegates.TryGetValue(typeof(T), out d))
        {
            Delegate currentDel = Delegate.Remove(d, listener);
 
            if (currentDel == null)
            {
                _delegates.Remove(typeof(T));
            }
            else
            {
                _delegates[typeof(T)] = currentDel;
            }
        }
    }
 
    public void Raise<T>(T e) where T : EventArgs
    {
        if (e == null)
        {
            throw new ArgumentNullException("e");
        }
 
        Delegate d;
        if (_delegates.TryGetValue(typeof(T), out d))
        {
            EventDelegate<T> callback = d as EventDelegate<T>;
            if (callback != null)
            {
                callback(e);
            }
        }
    }
}

EventArgs.cs

using UnityEngine;
using System.Collections;

public class UIEventArgs : EventArgs {
	
	private bool _isOpen;
	public bool IsOpen
	{
		get
		{
			return _isOpen;
		}
		set
		{
			_isOpen = value;
		}
	}
}

EventListener.cs（绑定在一个物体上）

using UnityEngine;
using System.Collections;

public class EventListener : MonoBehaviour {

	// Use this for initialization
	void Start () {
	   EventManager.Instance.AddListener<UIEventArgs>(OnReceive);
	}
	void OnReceive(UIEventArgs e)
	{
		if(e.IsOpen)
		{
			print ("Name:"+gameObject.name);
		}
	}
	
}

SendEventMeg.cs  (绑定在一个物体上)

using UnityEngine;
using System.Collections;

public class SendEventMeg : MonoBehaviour {

	// Use this for initialization
	void Start () {
	   
	}
	
	void Send ()
	{
		var arg = new UIEventArgs()
		{
	        IsOpen = true,
		};
		EventManager.Instance.Raise(arg);
	}
	void OnGUI()
	{
		if(GUILayout.Button("Send"))
		{
			Send();
		}
	}
}

结果：打印出“Name:xxxxx”.