unity 3d 使用C#的事件/委托机制

转自：http://blog.csdn.net/hiramtan/article/details/8955472

事件分发：

using UnityEngine;  public class EventDispatcher : MonoBehaviour {    public delegate void EventHandler(GameObject e);    public event EventHandler MouseOver;    void OnMouseOver () {      if (MouseOver != null)          MouseOver (this.gameObject);    }  }  

事件监听：

private GameObject s;  [...]  s.GetComponent<EventDispatcher>().MouseOver += Listener;  [...]  void Listener(GameObject g) {     // g is being hovered, do something...  }  

结束监听某个事件：

s.GetComponent<EventDispatcher>().MouseOver -= Listener;  

一个通用的EventDispatcher类，实现所有GameObject能够分发的事件。

using UnityEngine;  using System.Collections;    /**   *  A simple event dispatcher - allows to listen to events in one GameObject from another GameObject  *  *  Author: Bartek Drozdz (bartek [at] everyday3d [dot] com)  *  *  Usage:  *  Add this script to the object that is supposed to dispatch events.   *  In another objects follow this pattern to register as listener at intercept events:       void Start () {         EventDispatcher ev = GameObject.Find("someObject").GetComponent<EventDispatcher>();         ev.MouseDown += ListeningFunction; // Register the listener (and experience the beauty of overloaded operators!)     }      void ListeningFunction (GameObject e) {         e.transform.Rotate(20, 0, 0); // 'e' is the game object that dispatched the event         e.GetComponent<EventDispatcher>().MouseDown -= ListeningFunction; // Remove the listener     }       *  This class does not implement all standards events, nor does it allow dispatching custom events,   *  but you shold have no problem adding all the other methods.  */  public class EventDispatcher : MonoBehaviour  {        public delegate void EventHandler (GameObject e);      public delegate void CollisionHandler (GameObject e, Collision c);        public event EventHandler MouseOver;      void OnMouseOver ()      {          if (MouseOver != null)              MouseOver (this.gameObject);      }        public event EventHandler MouseDown;      void OnMouseDown ()      {          if (MouseDown != null)              MouseDown (this.gameObject);      }        public event EventHandler MouseEnter;      void OnMouseEnter ()      {          if (MouseEnter != null)              MouseEnter (this.gameObject);      }          public event EventHandler MouseExit;      void OnMouseExit ()      {          if (MouseExit != null)              MouseExit (this.gameObject);      }        public event EventHandler BecameVisible;      void OnBecameVisible ()      {          if (BecameVisible != null)              BecameVisible (this.gameObject);      }        public event EventHandler BecameInvisible;      void OnBecameInvisible ()      {          if (BecameInvisible != null)              BecameInvisible (this.gameObject);      }        public event CollisionHandler CollisionEnter;      void OnCollisionEnter (Collision c)      {          if (CollisionEnter != null)              CollisionEnter (this.gameObject, c);      }        public event CollisionHandler CollisionExit;      void OnCollisionExit (Collision c)      {          if (CollisionExit != null)              CollisionExit (this.gameObject, c);      }        }