转载自 :http://wiki.unity3d.com/index.php?title=Advanced_CSharp_Messenger
先进CSharp信使
作者:Ilya Suzdalnitski
内容( 隐藏 ]
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描述
这是一个先进的c#版本的消息传递系统。 它会自动清理事件表在一个新的水平加载。 这将防止程序员意外调用销毁方法,从而有助于防止许多MissingReferenceExceptions。 这个消息传递系统是基于杆海德 CSharpMessenger 和马格努斯Wolffelt CSharpMessenger扩展 。
前言
在消息传递系统引入我们的项目( CSharpMessenger扩展 )我们开始面临非常奇怪的错误。 Unity3d会把MissingReferenceExceptions每次广播消息。 它会说,类,消息处理程序中声明,被毁。 问题从哪里来的,没有一个合理的解释。 然而将消息处理程序代码在try - catch块解决了这个问题。 我们明白,这不是一个好的解决方案有成百上千的try - catch块在我们的代码。 我们花了一些时间来最后找出问题在哪里。
MissingReferenceException背后的原因和解决方案
原来,MissingReferenceException错误出现了,当一个新的水平加载当前(或重新加载)。 例如,我们有一个消息 “开始游戏” 宣布如下:
public class MainMenu : MonoBehaviour {
void Start ()
{
Messenger.AddListener("start game", StartGame);
}
void StartGame()
{
Debug.Log("StartGame called in" + gameObject); //This is the line that would throw an exception
}
void StartGameButtonPressed()
{
Messenger.Broadcast("start game");
}
} 乍一看,没有问题,但是水平加载后,Unity3d将抛出一个异常,称MainMenu已被摧毁。 然而没有代码,会破坏MainMenu脚本。
到底发生了什么:
- 我们添加了一个“开始游戏”对我们的信使消息侦听器。
- StartGameButtonPressed叫反过来播放“开始游戏”消息。
- 我们用Application.LoadLevel水平加载。
- 重复步骤1。
- 重复步骤2。
这里有eventTable使者的样子的相应的步骤:
- 在步骤1:{ “开始游戏”,mainMenu1 - > StartGame(); }
- 在步骤4:{ “开始游戏”,mainMenu1 - > StartGame(); } { “开始游戏”,mainMenu2 - > StartGame(); }
所以在第四步我们有两个相同的消息处理程序 “开始游戏” 消息——第一个是摧毁MainMenu对象(被破坏时重新加载一个级别),而第二种它为当前有效MainMenu对象。 事实证明,当我们广播的 “开始游戏” 消息后重新加载水平,信使调用——摧毁和有效的消息处理程序。 这就是MissingReferenceException来自的地方。
因此,显而易见——明确的解决方案 eventTable 卸货后的水平。 没有什么别的程序员是他清理桌子,它是自动完成的。
的信使
我们很高兴提供你一个高级版本的c#消息传递系统。
使用
事件监听器
void OnPropCollected( PropType propType ) {
if (propType == PropType.Life)
livesAmount++;
} 注册一个事件侦听器
void Start() {
Messenger.AddListener< Prop >( "prop collected", OnPropCollected );
} 取消注册一个事件侦听器
Messenger.RemoveListener< Prop > ( "prop collected", OnPropCollected ); 广播事件
public void OnTriggerEnter(Collider _collider)
{
Messenger.Broadcast< PropType > ( "prop collected", _collider.gameObject.GetComponent<Prop>().propType );
} 清理信使
信使清理其eventTable时自动加载一个新的水平。 这将确保eventTable信使的清理,将从意想不到的MissingReferenceExceptions拯救我们。 如果你想手动清理经理eventTable,有这样一个选项通过调用Messenger.Cleanup();
永久的消息
如果你想要某个消息生存清理,马克与Messenger.MarkAsPermanent(字符串)。 这可能需要如果某个类响应消息播放来自不同的水平。
Misc
记录所有消息
用于调试目的,您可以设置 shouldLogAllMessages 国旗在信使为true。 这将记录所有调用信使。
从其他使者
快速改变旧的CSharpMessenger所有调用消息传递系统的先进,做以下步骤:
- 在MonoDevelop去搜索= >替换文件
- 在找到字段输入: 信使号<([^ < >]+)>([A-Za-z0-9_]+)。
- 在替换字段输入: 信使。< $ 1 > 2美元
- 选择范围:整体解决方案。
- 检查正则表达式搜索”复选框。
- 按更换按钮
代码
有两个文件所需的信使——工作 Callback.cs 和 Messenger.cs 。
Callback.cs
public delegate void Callback();
public delegate void Callback<T>(T arg1);
public delegate void Callback<T, U>(T arg1, U arg2);
public delegate void Callback<T, U, V>(T arg1, U arg2, V arg3); Messenger.cs
/*
* Advanced C# messenger by Ilya Suzdalnitski. V1.0
*
* Based on Rod Hyde's "CSharpMessenger" and Magnus Wolffelt's "CSharpMessenger Extended".
*
* Features:
* Prevents a MissingReferenceException because of a reference to a destroyed message handler.
* Option to log all messages
* Extensive error detection, preventing silent bugs
*
* Usage examples:
1. Messenger.AddListener<GameObject>("prop collected", PropCollected);
Messenger.Broadcast<GameObject>("prop collected", prop);
2. Messenger.AddListener<float>("speed changed", SpeedChanged);
Messenger.Broadcast<float>("speed changed", 0.5f);
*
* Messenger cleans up its evenTable automatically upon loading of a new level.
*
* Don't forget that the messages that should survive the cleanup, should be marked with Messenger.MarkAsPermanent(string)
*
*/
//#define LOG_ALL_MESSAGES
//#define LOG_ADD_LISTENER
//#define LOG_BROADCAST_MESSAGE
#define REQUIRE_LISTENER
using System;
using System.Collections.Generic;
using UnityEngine;
static internal class Messenger {
#region Internal variables
//Disable the unused variable warning
#pragma warning disable 0414
//Ensures that the MessengerHelper will be created automatically upon start of the game.
static private MessengerHelper messengerHelper = ( new GameObject("MessengerHelper") ).AddComponent< MessengerHelper >();
#pragma warning restore 0414
static public Dictionary<string, Delegate> eventTable = new Dictionary<string, Delegate>();
//Message handlers that should never be removed, regardless of calling Cleanup
static public List< string > permanentMessages = new List< string > ();
#endregion
#region Helper methods
//Marks a certain message as permanent.
static public void MarkAsPermanent(string eventType) {
#if LOG_ALL_MESSAGES
Debug.Log("Messenger MarkAsPermanent \t\"" + eventType + "\"");
#endif
permanentMessages.Add( eventType );
}
static public void Cleanup()
{
#if LOG_ALL_MESSAGES
Debug.Log("MESSENGER Cleanup. Make sure that none of necessary listeners are removed.");
#endif
List< string > messagesToRemove = new List<string>();
foreach (KeyValuePair<string, Delegate> pair in eventTable) {
bool wasFound = false;
foreach (string message in permanentMessages) {
if (pair.Key == message) {
wasFound = true;
break;
}
}
if (!wasFound)
messagesToRemove.Add( pair.Key );
}
foreach (string message in messagesToRemove) {
eventTable.Remove( message );
}
}
static public void PrintEventTable()
{
Debug.Log("\t\t\t=== MESSENGER PrintEventTable ===");
foreach (KeyValuePair<string, Delegate> pair in eventTable) {
Debug.Log("\t\t\t" + pair.Key + "\t\t" + pair.Value);
}
Debug.Log("\n");
}
#endregion
#region Message logging and exception throwing
static public void OnListenerAdding(string eventType, Delegate listenerBeingAdded) {
#if LOG_ALL_MESSAGES || LOG_ADD_LISTENER
Debug.Log("MESSENGER OnListenerAdding \t\"" + eventType + "\"\t{" + listenerBeingAdded.Target + " -> " + listenerBeingAdded.Method + "}");
#endif
if (!eventTable.ContainsKey(eventType)) {
eventTable.Add(eventType, null );
}
Delegate d = eventTable[eventType];
if (d != null && d.GetType() != listenerBeingAdded.GetType()) {
throw new ListenerException(string.Format("Attempting to add listener with inconsistent signature for event type {0}. Current listeners have type {1} and listener being added has type {2}", eventType, d.GetType().Name, listenerBeingAdded.GetType().Name));
}
}
static public void OnListenerRemoving(string eventType, Delegate listenerBeingRemoved) {
#if LOG_ALL_MESSAGES
Debug.Log("MESSENGER OnListenerRemoving \t\"" + eventType + "\"\t{" + listenerBeingRemoved.Target + " -> " + listenerBeingRemoved.Method + "}");
#endif
if (eventTable.ContainsKey(eventType)) {
Delegate d = eventTable[eventType];
if (d == null) {
throw new ListenerException(string.Format("Attempting to remove listener with for event type \"{0}\" but current listener is null.", eventType));
} else if (d.GetType() != listenerBeingRemoved.GetType()) {
throw new ListenerException(string.Format("Attempting to remove listener with inconsistent signature for event type {0}. Current listeners have type {1} and listener being removed has type {2}", eventType, d.GetType().Name, listenerBeingRemoved.GetType().Name));
}
} else {
throw new ListenerException(string.Format("Attempting to remove listener for type \"{0}\" but Messenger doesn't know about this event type.", eventType));
}
}
static public void OnListenerRemoved(string eventType) {
if (eventTable[eventType] == null) {
eventTable.Remove(eventType);
}
}
static public void OnBroadcasting(string eventType) {
#if REQUIRE_LISTENER
if (!eventTable.ContainsKey(eventType)) {
throw new BroadcastException(string.Format("Broadcasting message \"{0}\" but no listener found. Try marking the message with Messenger.MarkAsPermanent.", eventType));
}
#endif
}
static public BroadcastException CreateBroadcastSignatureException(string eventType) {
return new BroadcastException(string.Format("Broadcasting message \"{0}\" but listeners have a different signature than the broadcaster.", eventType));
}
public class BroadcastException : Exception {
public BroadcastException(string msg)
: base(msg) {
}
}
public class ListenerException : Exception {
public ListenerException(string msg)
: base(msg) {
}
}
#endregion
#region AddListener
//No parameters
static public void AddListener(string eventType, Callback handler) {
OnListenerAdding(eventType, handler);
eventTable[eventType] = (Callback)eventTable[eventType] + handler;
}
//Single parameter
static public void AddListener<T>(string eventType, Callback<T> handler) {
OnListenerAdding(eventType, handler);
eventTable[eventType] = (Callback<T>)eventTable[eventType] + handler;
}
//Two parameters
static public void AddListener<T, U>(string eventType, Callback<T, U> handler) {
OnListenerAdding(eventType, handler);
eventTable[eventType] = (Callback<T, U>)eventTable[eventType] + handler;
}
//Three parameters
static public void AddListener<T, U, V>(string eventType, Callback<T, U, V> handler) {
OnListenerAdding(eventType, handler);
eventTable[eventType] = (Callback<T, U, V>)eventTable[eventType] + handler;
}
#endregion
#region RemoveListener
//No parameters
static public void RemoveListener(string eventType, Callback handler) {
OnListenerRemoving(eventType, handler);
eventTable[eventType] = (Callback)eventTable[eventType] - handler;
OnListenerRemoved(eventType);
}
//Single parameter
static public void RemoveListener<T>(string eventType, Callback<T> handler) {
OnListenerRemoving(eventType, handler);
eventTable[eventType] = (Callback<T>)eventTable[eventType] - handler;
OnListenerRemoved(eventType);
}
//Two parameters
static public void RemoveListener<T, U>(string eventType, Callback<T, U> handler) {
OnListenerRemoving(eventType, handler);
eventTable[eventType] = (Callback<T, U>)eventTable[eventType] - handler;
OnListenerRemoved(eventType);
}
//Three parameters
static public void RemoveListener<T, U, V>(string eventType, Callback<T, U, V> handler) {
OnListenerRemoving(eventType, handler);
eventTable[eventType] = (Callback<T, U, V>)eventTable[eventType] - handler;
OnListenerRemoved(eventType);
}
#endregion
#region Broadcast
//No parameters
static public void Broadcast(string eventType) {
#if LOG_ALL_MESSAGES || LOG_BROADCAST_MESSAGE
Debug.Log("MESSENGER\t" + System.DateTime.Now.ToString("hh:mm:ss.fff") + "\t\t\tInvoking \t\"" + eventType + "\"");
#endif
OnBroadcasting(eventType);
Delegate d;
if (eventTable.TryGetValue(eventType, out d)) {
Callback callback = d as Callback;
if (callback != null) {
callback();
} else {
throw CreateBroadcastSignatureException(eventType);
}
}
}
//Single parameter
static public void Broadcast<T>(string eventType, T arg1) {
#if LOG_ALL_MESSAGES || LOG_BROADCAST_MESSAGE
Debug.Log("MESSENGER\t" + System.DateTime.Now.ToString("hh:mm:ss.fff") + "\t\t\tInvoking \t\"" + eventType + "\"");
#endif
OnBroadcasting(eventType);
Delegate d;
if (eventTable.TryGetValue(eventType, out d)) {
Callback<T> callback = d as Callback<T>;
if (callback != null) {
callback(arg1);
} else {
throw CreateBroadcastSignatureException(eventType);
}
}
}
//Two parameters
static public void Broadcast<T, U>(string eventType, T arg1, U arg2) {
#if LOG_ALL_MESSAGES || LOG_BROADCAST_MESSAGE
Debug.Log("MESSENGER\t" + System.DateTime.Now.ToString("hh:mm:ss.fff") + "\t\t\tInvoking \t\"" + eventType + "\"");
#endif
OnBroadcasting(eventType);
Delegate d;
if (eventTable.TryGetValue(eventType, out d)) {
Callback<T, U> callback = d as Callback<T, U>;
if (callback != null) {
callback(arg1, arg2);
} else {
throw CreateBroadcastSignatureException(eventType);
}
}
}
//Three parameters
static public void Broadcast<T, U, V>(string eventType, T arg1, U arg2, V arg3) {
#if LOG_ALL_MESSAGES || LOG_BROADCAST_MESSAGE
Debug.Log("MESSENGER\t" + System.DateTime.Now.ToString("hh:mm:ss.fff") + "\t\t\tInvoking \t\"" + eventType + "\"");
#endif
OnBroadcasting(eventType);
Delegate d;
if (eventTable.TryGetValue(eventType, out d)) {
Callback<T, U, V> callback = d as Callback<T, U, V>;
if (callback != null) {
callback(arg1, arg2, arg3);
} else {
throw CreateBroadcastSignatureException(eventType);
}
}
}
#endregion
}
//This manager will ensure that the messenger's eventTable will be cleaned up upon loading of a new level.
public sealed class MessengerHelper : MonoBehaviour {
void Awake ()
{
DontDestroyOnLoad(gameObject);
}
//Clean up eventTable every time a new level loads.
public void OnLevelWasLoaded(int unused) {
Messenger.Cleanup();
}
} ![C#基础——与C#的第一次邂逅声明：IDE：第一个C#果实：Console浅析：总结：[图]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)