一、前言:
在游戏开发的很多时候,需要引用其他类的方法,但是一旦类多起来了,相互引用会导致引用关系混乱,极其难以阅读。
以前初次做抖音小游戏时,和一位经验老道的cocos程序员合作,看到我写的代码他不禁皱起眉头,说我的引用关系太乱了,看不懂,但是他又不知道unity的事件派发器怎么写,就去网上找了一个。简直惊艳到我了。后来在现在公司做,又见到了一种事件派发器,于是心生感慨,模仿写了一个,并写博客记录一下。
二、现在做的事件派发器
1.声明对应的委托,此委托主要为事件用的。委托的所有返回类型都为Void,简化派发器的复杂程度;明确委托的方法参数类型,有几种类型就定义几种委托。
public delegate void VoidDelegate(); public delegate void BoolDelegate(params bool[] parameters); public delegate void NumberDelegate(params float[] parameters); public delegate void GameObjectDelegate(params GameObject[] parameters);
2.存储容器,用于存储事件
private static List<VoidDelegate> GameStart_List;
3.监听者,暴露给外部调用者的接口,对监听者的+=或-=对应容器里的Add和Remove
public static event VoidDelegate GameStart_Listener { add { if(value != null) { if(GameStart_List == null) { GameStart_List = new List<VoidDelegate>(1); } GameStart_List.Add(value); } } remove { if(value != null) { for(int i = 0;i<GameStart_List.Count;i++) { if(GameStart_List[i] != null && GameStart_List[i].Equals(value)) { GameStart_List.RemoveAt(i); break; } } } } }
4.派发者,因为event只能在声明类内部Invoke,所以需要暴露给外部调用者接口
public static void GameStart_Dispatch() { if(GameStart_List == null || GameStart_List.Count <= 0) { return; } for(int i = 0;i < GameStart_List.Count;i++) { GameStart_List[i]?.Invoke(); } }
5.上文可看见我的事件叫GameStart,那么我想新增一个GameEnd的事件,岂不是又要写一遍?而且假如我的方法参数是float呢?是bool呢?是GameObject呢?岂不是改动很大?所以我在Unity做了一个自动生成事件的工具
5.1 定义ScriptObject作为配置文件,可随时修改以添加或者删除事件
[CreateAssetMenu] public class EventHandlerSetting:ScriptableObject { public List<EventType> types; public List<EventItem> items; } [System.Serializable] public class EventItem { public string eventName; public string typeName; } [System.Serializable] public class EventType { public string typeName; public string typeDelegate; }
5.2 自动生成脚本工具
using System.Collections; using System.Collections.Generic; using UnityEngine; using UnityEditor; using System.IO; using System.Text; using System.Text.RegularExpressions; public class CodeGen { private static string SettingPath = @"EventHandleSetting"; private static EventHandlerSetting SettingObj; private static string CodePath = @"Assets/EventHandler/"; private static string CodeName = "EventHandler.cs"; private static string LineFeed = "/r/n"; private static string LineTable = "/t"; [MenuItem("Tools/EventCodeGen")] public static void CreateEventCode() { if (File.Exists(CodePath+CodeName)) { File.Delete(CodePath + CodeName); } File.Create(CodePath + CodeName).Dispose(); LoadSetting(); File.AppendAllText(CodePath + CodeName, CreateNamespace()); File.AppendAllText(CodePath + CodeName, CreateDelegate()); File.AppendAllText(CodePath + CodeName, CreateClass()); AssetDatabase.Refresh(); } /// <summary> /// 加载配置文件 /// </summary> static void LoadSetting() { SettingObj = Resources.Load<EventHandlerSetting>(SettingPath); } static string CreateNamespace() { StringBuilder result = new StringBuilder(); result.Append("using System;" + LineFeed); result.Append("using System.Collections;" + LineFeed); result.Append("using System.Collections.Generic;" + LineFeed); result.Append("using UnityEngine;" + LineFeed+LineFeed); return result.ToString(); } /// <summary> /// 创建委托类型 /// </summary> /// <returns></returns> static string CreateDelegate() { StringBuilder result = new StringBuilder(); string commnPrefix = "public delegate void "; using (var e = SettingObj.types.GetEnumerator()) { while (e.MoveNext()) { result.Append(commnPrefix + e.Current.typeDelegate + ";" + LineFeed); } } result.Append(LineFeed); return result.ToString(); } /// <summary> /// 创建EventHandler类 /// </summary> /// <returns></returns> static string CreateClass() { StringBuilder result = new StringBuilder(); result.Append("public class EventHandler"+LineFeed); result.Append("{"+LineFeed); List<EventItem> ls = SettingObj.items; for (int i = 0; i < ls.Count; i++) { string eventName = ls[i].eventName; string eventType = ls[i].typeName; result.Append(CreateEvent(eventName, eventType)); } result.Append("}"); return result.ToString(); } /// <summary> /// 创建事件派发器 /// </summary> /// <param name="eventName"></param> /// <param name="eventType"></param> /// <returns></returns> static string CreateEvent(string eventName,string eventType) { StringBuilder result = new StringBuilder(); result.Append(LineFeed + "#region " + eventName + LineFeed); result.Append(MutiLineTable(1) + string.Format("private static List<{0}> {1}_List;", eventType + "Delegate", eventName) + LineFeed);//创建List result.Append(CreateListener(eventName, eventType)); result.Append(CreateDispatch(eventName, eventType)); result.Append("#endregion"+LineFeed); return result.ToString(); } /// <summary> /// 创建Listener /// </summary> /// <param name="eventName"></param> /// <param name="eventType"></param> /// <returns></returns> static string CreateListener(string eventName,string eventType) { StringBuilder result = new StringBuilder(); result.Append(MutiLineTable(1) + string.Format("public static event {0} {1}_Listener", eventType + "Delegate", eventName) + LineFeed); result.Append(MutiLineTable(1) + "{" + LineFeed); #region add result.Append(MutiLineTable(2) + "add" + LineFeed); result.Append(MutiLineTable(2) + "{" + LineFeed); result.Append(MutiLineTable(3) + "if(value != null)" + LineFeed); result.Append(MutiLineTable(3) + "{" + LineFeed); result.Append(MutiLineTable(4) + string.Format("if({0}_List == null)", eventName) + LineFeed); result.Append(MutiLineTable(4) + "{" + LineFeed); result.Append(MutiLineTable(5) + string.Format("{0}_List = new List<{1}>(1);", eventName, eventType + "Delegate")+LineFeed); result.Append(MutiLineTable(4) + "}" + LineFeed); result.Append(MutiLineTable(4) + string.Format("{0}_List.Add(value);", eventName) + LineFeed); result.Append(MutiLineTable(3) + "}" + LineFeed); result.Append(MutiLineTable(2) + "}" + LineFeed); #endregion #region remove result.Append(MutiLineTable(2) + "remove" + LineFeed); result.Append(MutiLineTable(2) + "{" + LineFeed); result.Append(MutiLineTable(3) + "if(value != null)" + LineFeed); result.Append(MutiLineTable(3) + "{" + LineFeed); result.Append(MutiLineTable(4) + string.Format("for(int i = 0;i<{0}_List.Count;i++)", eventName) + LineFeed); result.Append(MutiLineTable(4) + "{" + LineFeed); result.Append(MutiLineTable(5) + string.Format("if({0}_List[i] != null && {1}_List[i].Equals(value))",eventName,eventName) + LineFeed); result.Append(MutiLineTable(5) + "{" + LineFeed); result.Append(MutiLineTable(6) + string.Format("{0}_List.RemoveAt(i);" ,eventName) + LineFeed); result.Append(MutiLineTable(6) + "break;" + LineFeed); result.Append(MutiLineTable(5) + "}" + LineFeed); result.Append(MutiLineTable(4) + "}" + LineFeed); result.Append(MutiLineTable(3) + "}" + LineFeed); result.Append(MutiLineTable(2) + "}" + LineFeed); #endregion result.Append(MutiLineTable(1) + "}" + LineFeed); return result.ToString(); } /// <summary> /// 创建Dispatch /// </summary> /// <param name="eventName"></param> /// <param name="eventType"></param> /// <returns></returns> static string CreateDispatch(string eventName,string eventType) { StringBuilder result = new StringBuilder(); result.Append(MutiLineTable(1) + string.Format("public static void {0}_Dispatch({1})", eventName, GetTypeParameter(eventType)) + LineFeed); result.Append(MutiLineTable(1) + "{" + LineFeed); result.Append(MutiLineTable(2) + string.Format("if({0}_List == null || {1}_List.Count <= 0)", eventName, eventName) + LineFeed); result.Append(MutiLineTable(2) + "{" + LineFeed); result.Append(MutiLineTable(3) + "return;" + LineFeed); result.Append(MutiLineTable(2) + "}" + LineFeed); result.Append(MutiLineTable(2) + string.Format("for(int i = 0;i < {0}_List.Count;i++)", eventName) + LineFeed); result.Append(MutiLineTable(2) + "{" + LineFeed); if (!string.IsNullOrEmpty(GetTypeParameter(eventType))) { result.Append(MutiLineTable(3) + string.Format("{0}_List[i]?.Invoke(parameters[i]);", eventName) + LineFeed); } else { result.Append(MutiLineTable(3) + string.Format("{0}_List[i]?.Invoke();", eventName) + LineFeed); } result.Append(MutiLineTable(2) + "}" + LineFeed); result.Append(MutiLineTable(1) + "}" + LineFeed); return result.ToString(); } /// <summary> /// 获取字符串中括号中的内容 /// </summary> /// <param name="typeName"></param> /// <returns></returns> static string GetTypeParameter(string typeName) { if (string.IsNullOrEmpty(typeName)) { return string.Empty; } using (var e=SettingObj.types.GetEnumerator()) { while (e.MoveNext()) { if (e.Current.typeName==typeName) { string @delegate = e.Current.typeDelegate; string result = @delegate.Substring(@delegate.IndexOf("(") + 1, @delegate.IndexOf(")") - (@delegate.IndexOf("(") + 1)); Debug.Log(result); return result; } } } return string.Empty; } /// <summary> /// 多个table /// </summary> /// <param name="count"></param> /// <returns></returns> static string MutiLineTable(int count) { StringBuilder result = new StringBuilder(); for (int i = 0; i < count; i++) { result.Append(LineTable); } return result.ToString() ; } }
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6.总结
当然,我的这一套事件系统肯定还是有问题的。如果方法参数不止一个float呢?第二个参数是bool?组合起来呢?还有一个问题是,配置文件不够人性化,全部都是字符串,假如多大一个空格或者标点就废了。还有一个非常严重的问题,如果生成的脚本,在语法上有错,不能通过编译器,Unity就会报错,再次点击生成就不会生效。我认识的一个主程让我在Unity外部生成,不要依赖Unity,且使用类似Lua、Python这种脚本语言,目前还不会哈哈哈哈。
三、以前做的事件派发器
1.需要一个通用的参数类型,叫EventArgs,基础类型为Systen.Object
public class EventArgs { private List<System.Object> parameters; public int Count { get { if (parameters!=null) { return parameters.Count; } else { Debug.Log("parameters is not init"); return 0; } } } public EventArgs(params System.Object[] parameters) { if (this.parameters==null) { this.parameters = new List<object>(); } for (int i = 0; i < parameters.Length; i++) { this.parameters.Add(parameters[i]); } } public System.Object this[int index] { get { if (index>=0||index<parameters.Count) { return parameters[index]; } else { Debug.LogError("index must be in range of parameters"); return null; } } } }
2.还是那句老话,事件派发器需要容器、监听、派发三部分。
public class EventDispatcher { public delegate void Listener(EventArgs args); private static Dictionary<string, Listener> cacheEvents = new Dictionary<string, Listener>(); public static void Attach(string tag,Listener listen) { if (cacheEvents==null) { cacheEvents = new Dictionary<string, Listener>(); } if (cacheEvents.ContainsKey(tag)) { Debug.LogWarning("this tag already exsit in cache,please check agin,tag name:" + tag); return; } if (listen==null) { Debug.LogWarning("listen is null,cache failed"); return; } cacheEvents.Add(tag, listen); } public static void Detach(string tag) { if (!cacheEvents.ContainsKey(tag)) { Debug.LogWarning("tag is not exsit in cache,tag name:"+tag); return; } cacheEvents.Remove(tag); } public static void Dispatch(string tag,EventArgs args) { if (!cacheEvents.ContainsKey(tag)) { Debug.LogWarning("this tag does not exsit in cache,please check agin,tag name:" + tag); return; } if (cacheEvents[tag]==null) { Debug.LogWarning("this listen is null,invoke failed"); return; } cacheEvents[tag].Invoke(args); } }
3.总结:
此事件派发器也存在缺陷,任何方法的参数类型都会被转换成System.Object类型,有多余的封装箱操作。且不能重复添加一个方法,至少他的tag不能一样。代码可读性差,报错了都不知道在哪儿。
四、关于事件派发器自己的看法
我相信没有完美的派发器这一说,好的派发器与坏的派发器区别在于,调用是否方便?会不会存在隐藏的危险bug?性能上如何?不同项目有不同的事件派发器,适合自己的才是最好的。如果强行将事件派发器做成那种万金油工具,且不论他是否真的是万金油,代码开发成本之大,耗费时间之长,也不是一般小游戏公司能够耗得起的。上文所述两个派发器,实际上都可以用,而且经历过实战的,并没有什么大问题。