Unity3D C#事件管理:EventManager

原文地址：http://bbs.9ria.com/thread-153258-1-1.html

原project地址：https://github.com/djandrew/UnityEventManager

多年的Flash开发。我很赞赏Flash的事件系统。

Uinty对象通信所使用的方法SendMessage在多数情况下是工作正常，但假设在一个具有无数引用其它对象的GameObject的大型项目进行反射，那问题就来了。

我用C＃在Uinty中所写的第一个东西，就是管理抽象类的事件管理系统。

究其核心。EventManager使用也是SendMessage。并对游戏对象[gameObject]有直接引用，但若有事件发生。其便会对需求进行分解，不同的类间会有信息共享，这样事件对象就知道怎样互相通信。

若有不论什么建议或修正。欢迎留言。

EventManager.cs(十按。本链接为凝视译版，若认为某译不妥请对比英文版自行勘误)

1. /*
2. Event Manager
3. Static manager for handling an event driven communication model in Unity.
4. This is similar to Adobe Flash's event listener model used in ActionScript.
5. Copyright © 2012 Dustin Andrew
6. dustin.andrew@gmail.com
7. http://www.dustinandrew.me/
8. This program is free software: you can redistribute it and/or modify
9. it under the terms of the GNU General Public License as published by
10. the Free Software Foundation, either version 3 of the License, or
11. any later version.
12. This program is distributed in the hope that it will be useful,
13. but WITHOUT ANY WARRANTY; without even the implied warranty of
14. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15. GNU General Public License for more details.
16. http://www.gnu.org/licenses/
17. */
18. /*
19. *  Setup:
20. *  Create an empty GameObject and add the EventManager script to it.
21. *  Create custom event classes that extend the CustomEvent.
22. *
23. *  Restrictions & Tips:
24. *  DO NOT add event listeners in the Awake() method!
25. *  This is used by the EventManager to initialize.
26. *  Change this class' Execution Order to before default time if you need to work around this.
27. *  Use the Start() method to setup your events.
28. *  Make event listener callback functions public.
29. *  Extend the CustomEvent class when creating your events.
30. *  Use custom variables in your custom events over the arguments hashtable to maintain class abstraction
31. *  Clean up and remove event listeners when objects are destroyed.
32. *  Events are not received if the listener gameObject.active is false.
33. *
34. *  Examples:
35. *
36. *  // setup event listeners
37. *  void Start() {
38. *      EventManager.instance.addEventListener(CustomEventObj.EVENT_TO_LISTEN_TO, gameObject, "OnSomethingHappened");
39. *  }
40. *
41. *  // remove event listeners
42. *  void OnDestroy() {
43. *      if (gameObject) {
44. *          // remove a single event
45. *          EventManager.instance.removeEventListener(CustomEventObj.EVENT_TO_LISTEN_TO, gameObject);
46. *          // remove all events
47. *          EventManager.instance.removeAllEventListeners(gameObject);
48. *      }
49. *  }
50. *
51. *  // get values passed by events
52. *  public void OnSomethingHappened(CustomEventObj evt) {
53. *      Debug.Log((datatype)evt.arguments["value"]);
54. *      // or if using custom vars instead of arguments hashtable
55. *      Debug.Log(evt.rockOn);
56. *  }
57. *
58. *  // dispatch events
59. *  void TriggerEvent() {
60. *      CustomEventObj evt = new CustomEventObj(CustomEventObj.EVENT_TO_TRIGGER);
61. *      evt.arguments.Add("value", 3);
62. *      EventManager.instance.dispatchEvent(evt);
63. *  }
64. *
65. *  // create custom events
66. *  using UnityEngine;
67. *  using System.Collections;
68. *
69. *  public class CustomEventObj : CustomEvent {
70. *
71. *      // event types
72. *      public static string MY_EVENT_1 = "my_event_1";
73. *      public static string MY_EVENT_2 = "my_event_2";
74. *
75. *      // optionally add custom variables instead of using the arguments hashtable
76. *      public int myCustomEventVar1 = 0;
77. *      public bool rockOn = true;
78. *
79. *      public CustomEventObj(string eventType = "") {
80. *         type = eventType;
81. *      }
82. *  }
83. *
84. */
85. using UnityEngine;
86. using System.Collections;
87. // internal event listener model
88. internal class EventListener {
89. public string name;
90. public GameObject listener;
91. public string function;
92. }
93. // Custom event class, extend when creating custom events
94. public class CustomEvent {
95. private string _type;
96. private Hashtable _arguments = new Hashtable();
97. // constructor
98. public CustomEvent(string eventType = "") {
99. _type = eventType;
100. }
101. // the type of event
102. public string type {
103. get { return _type; }
104. set { _type = value; }
105. }
106. // the arguments to pass with the event
107. public Hashtable arguments {
108. get { return _arguments; }
109. set { _arguments = value; }
110. }
111. }
112. public class EventManager : MonoBehaviour {
113. // singleton instance
114. public static EventManager instance;
115. // settings
116. public bool allowSingleton = true; // EventManager class will transfer between scene changes.
117. public bool allowWarningOutputs = true;
118. public bool allowDebugOutputs = true;
119. private static bool _created = false;
120. private Hashtable _listeners = new Hashtable();
121. // setup singleton if allowed
122. public void Awake() {
123. if (!_created && allowSingleton) {
124. DontDestroyOnLoad(this);
125. instance = this;
126. _created = true;
127. Setup();
128. } else {
129. if (allowSingleton) {
130. if (EventManager.instance.allowWarningOutputs) {
131. Debug.LogWarning("Only a single instance of " + this.name + " should exists!");
132. }
133. Destroy(gameObject);
134. } else {
135. instance = this;
136. Setup();
137. }
138. }
139. }
140. // clear events on quit
141. public void OnApplicationQuit() {
142. _listeners.Clear();
143. }
144. // PUBLIC *******************************
145. // Add event listener
146. public bool addEventListener(string eventType, GameObject listener, string function) {
147. if (listener == null || eventType == null) {
148. if (allowWarningOutputs) {
149. Debug.LogWarning("Event Manager: AddListener failed due to no listener or event name specified.");
150. }
151. return false;
152. }
153. recordEvent(eventType);
154. return recordListener(eventType, listener, function);
155. }
156. // Remove event listener
157. public bool removeEventListener(string eventType, GameObject listener) {
158. if (!checkForEvent(eventType)) return false;
159. ArrayList listenerList = _listeners[eventType] as ArrayList;
160. foreach (EventListener callback in listenerList) {
161. if (callback.name == listener.GetInstanceID().ToString()) {
162. listenerList.Remove(callback);
163. return true;
164. }
165. }
166. return false;
167. }
168. // Remove all event listeners
169. public void removeAllEventListeners(GameObject listener) {
170. foreach (EventListener callback in _listeners) {
171. if (callback.listener.GetInstanceID().ToString() == listener.GetInstanceID().ToString()) {
172. _listeners.Remove(callback);
173. }
174. }
175. }
176. // Dispatch an event
177. public bool dispatchEvent(CustomEvent evt) {
178. string eventType = evt.type;
179. if (!checkForEvent(eventType)) {
180. if (allowWarningOutputs) {
181. Debug.LogWarning("Event Manager: Event \"" + eventType + "\" triggered has no listeners!");
182. }
183. return false;
184. }
185. ArrayList listenerList = _listeners[eventType] as ArrayList;
186. if (allowDebugOutputs) {
187. Debug.Log("Event Manager: Event " + eventType + " dispatched to " + listenerList.Count + ((listenerList.Count == 1) ? " listener." : " listeners."));
188. }
189. foreach (EventListener callback in listenerList) {
190. if (callback.listener && callback.listener.active) {
191. callback.listener.SendMessage(callback.function, evt, SendMessageOptions.DontRequireReceiver);
192. }
193. }
194. return false;
195. }
196. // PRIVATE *******************************
197. private void Setup() {
198. // TO DO: Self create GameObject if not already created
199. }
200. // see if event already exists
201. private bool checkForEvent(string eventType) {
202. if (_listeners.ContainsKey(eventType)) return true;
203. return false;
204. }
205. // record event, if it doesn't already exists
206. private bool recordEvent(string eventType) {
207. if (!checkForEvent(eventType)) {
208. _listeners.Add(eventType, new ArrayList());
209. }
210. return true;
211. }
212. // delete event, if not already removed
213. private bool deleteEvent(string eventType) {
214. if (!checkForEvent(eventType)) return false;
215. _listeners.Remove(eventType);
216. return true;
217. }
218. // check if listener exists
219. private bool checkForListener(string eventType, GameObject listener) {
220. if (!checkForEvent(eventType)) {
221. recordEvent(eventType);
222. }
223. ArrayList listenerList = _listeners[eventType] as ArrayList;
224. foreach (EventListener callback in listenerList) {
225. if (callback.name == listener.GetInstanceID().ToString()) return true;
226. }
227. return false;
228. }
229. // record listener, if not already recorded
230. private bool recordListener(string eventType, GameObject listener, string function) {
231. if (!checkForListener(eventType, listener)) {
232. ArrayList listenerList = _listeners[eventType] as ArrayList;
233. EventListener callback = new EventListener();
234. callback.name = listener.GetInstanceID().ToString();
235. callback.listener = listener;
236. callback.function = function;
237. listenerList.Add(callback);
238. return true;
239. } else {
240. if (allowWarningOutputs) {
241. Debug.LogWarning("Event Manager: Listener: " + listener.name + " is already in list for event: " + eventType);
242. }
243. return false;
244. }
245. }
246. }

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原文链接：http://www.dustinandrew.me/blog/2012/10/9/unity3d-c-event-manager.html

翻译词数：225