Unity 之事件系统

游戏开发过程中事件是非常多的，可以通过 Messenger 事件系统来解藕，用法如下：

使用方法

例子：在按下拍照按钮后通知刷新好友面板
步骤1、添加事件字段，该字段具有唯一性
        在MessangerEventDef脚本（可以每个功能都有一个事件字段脚本，类似于消息）中添加字段"Demo_EventType".

步骤2、广播事件：在按下拍照按钮方法中调用
        Messenger.Broadcast(MessangerEventDef.Demo_EventType);

步骤3、在OnEnable()方法中注册事件：在FriendUI_Ctrl中的OnEnable方法中添加
        Messenger.AddListener(MessangerEventDef.Demo_EventType, OnCall);

步骤4、在OnDisable()方法中移除事件：在FriendUI_Ctrl中的OnDisable方法中添加
        Messenger.RemoveListener(MessangerEventDef.Demo_EventType, OnCall);

        void OnCall()
        {
            Debug.LogError("===OnCall==");
            //TODO 刷新好友相关代码
        }

注意事项
    1、AddListener和RemoveListener必须成对出现。

代码如下：

// Messenger.cs v1.0 by Magnus Wolffelt, magnus.wolffelt@gmail.com
//
// Inspired by and based on Rod Hyde's Messenger:
// http://www.unifycommunity.com/wiki/index.php?title=CSharpMessenger
//
// This is a C# messenger (notification center). It uses delegates
// and generics to provide type-checked messaging between event producers and
// event consumers, without the need for producers or consumers to be aware of
// each other. The major improvement from Hyde's implementation is that
// there is more extensive error detection, preventing silent bugs.
//
// Usage example:
// Messenger<float>.AddListener("myEvent", MyEventHandler);
// ...
// Messenger<float>.Broadcast("myEvent", 1.0f);


using System;
using System.Collections.Generic;

namespace Common.Messenger
{
    public enum MessengerMode : byte
    {
        DONT_REQUIRE_LISTENER,
        REQUIRE_LISTENER,
    }


    static internal class MessengerInternal
    {
        static public Dictionary<string, Delegate> eventTable = new Dictionary<string, Delegate>();
        static public readonly MessengerMode DEFAULT_MODE = MessengerMode.DONT_REQUIRE_LISTENER;

        static public void OnListenerAdding(string eventType, Delegate listenerBeingAdded)
        {
            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 (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, MessengerMode mode)
        {
            if (mode == MessengerMode.REQUIRE_LISTENER && !eventTable.ContainsKey(eventType))
            {
                throw new MessengerInternal.BroadcastException(string.Format("Broadcasting message {0} but no listener found.", eventType));
            }
        }

        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)
            {
            }
        }
    }


    // No parameters
    static public class Messenger
    {
        private static Dictionary<string, Delegate> eventTable = MessengerInternal.eventTable;

        static public void AddListener(string eventType, Callback handler)
        {
            MessengerInternal.OnListenerAdding(eventType, handler);
            eventTable[eventType] = (Callback)eventTable[eventType] + handler;
        }

        static public void RemoveListener(string eventType, Callback handler)
        {
            MessengerInternal.OnListenerRemoving(eventType, handler);
            eventTable[eventType] = (Callback)eventTable[eventType] - handler;
            MessengerInternal.OnListenerRemoved(eventType);
        }

        static public void Broadcast(string eventType)
        {
            Broadcast(eventType, MessengerInternal.DEFAULT_MODE);
        }

        static public void Broadcast(string eventType, MessengerMode mode)
        {
            MessengerInternal.OnBroadcasting(eventType, mode);
            Delegate d;
            if (eventTable.TryGetValue(eventType, out d))
            {
                Callback callback = d as Callback;
                if (callback != null)
                {
                    callback();
                }
                else
                {
                    throw MessengerInternal.CreateBroadcastSignatureException(eventType);
                }
            }
        }
    }

    // One parameter
    static public class Messenger<T>
    {
        private static Dictionary<string, Delegate> eventTable = MessengerInternal.eventTable;

        static public void AddListener(string eventType, Callback<T> handler)
        {
            MessengerInternal.OnListenerAdding(eventType, handler);
            eventTable[eventType] = (Callback<T>)eventTable[eventType] + handler;
        }

        static public void RemoveListener(string eventType, Callback<T> handler)
        {
            MessengerInternal.OnListenerRemoving(eventType, handler);
            eventTable[eventType] = (Callback<T>)eventTable[eventType] - handler;
            MessengerInternal.OnListenerRemoved(eventType);
        }

        static public void Broadcast(string eventType, T arg1)
        {
            Broadcast(eventType, arg1, MessengerInternal.DEFAULT_MODE);
        }

        static public void Broadcast(string eventType, T arg1, MessengerMode mode)
        {
            MessengerInternal.OnBroadcasting(eventType, mode);
            Delegate d;
            if (eventTable.TryGetValue(eventType, out d))
            {
                Callback<T> callback = d as Callback<T>;
                if (callback != null)
                {
                    callback(arg1);
                }
                else
                {
                    throw MessengerInternal.CreateBroadcastSignatureException(eventType);
                }
            }
        }
    }


    // Two parameters
    static public class Messenger<T, U>
    {
        private static Dictionary<string, Delegate> eventTable = MessengerInternal.eventTable;

        static public void AddListener(string eventType, Callback<T, U> handler)
        {
            MessengerInternal.OnListenerAdding(eventType, handler);
            eventTable[eventType] = (Callback<T, U>)eventTable[eventType] + handler;
        }

        static public void RemoveListener(string eventType, Callback<T, U> handler)
        {
            MessengerInternal.OnListenerRemoving(eventType, handler);
            eventTable[eventType] = (Callback<T, U>)eventTable[eventType] - handler;
            MessengerInternal.OnListenerRemoved(eventType);
        }

        static public void Broadcast(string eventType, T arg1, U arg2)
        {
            Broadcast(eventType, arg1, arg2, MessengerInternal.DEFAULT_MODE);
        }

        static public void Broadcast(string eventType, T arg1, U arg2, MessengerMode mode)
        {
            MessengerInternal.OnBroadcasting(eventType, mode);
            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 MessengerInternal.CreateBroadcastSignatureException(eventType);
                }
            }
        }
    }


    // Three parameters
    static public class Messenger<T, U, V>
    {
        private static Dictionary<string, Delegate> eventTable = MessengerInternal.eventTable;

        static public void AddListener(string eventType, Callback<T, U, V> handler)
        {
            MessengerInternal.OnListenerAdding(eventType, handler);
            eventTable[eventType] = (Callback<T, U, V>)eventTable[eventType] + handler;
        }

        static public void RemoveListener(string eventType, Callback<T, U, V> handler)
        {
            MessengerInternal.OnListenerRemoving(eventType, handler);
            eventTable[eventType] = (Callback<T, U, V>)eventTable[eventType] - handler;
            MessengerInternal.OnListenerRemoved(eventType);
        }

        static public void Broadcast(string eventType, T arg1, U arg2, V arg3)
        {
            Broadcast(eventType, arg1, arg2, arg3, MessengerInternal.DEFAULT_MODE);
        }

        static public void Broadcast(string eventType, T arg1, U arg2, V arg3, MessengerMode mode)
        {
            MessengerInternal.OnBroadcasting(eventType, mode);
            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 MessengerInternal.CreateBroadcastSignatureException(eventType);
                }
            }
        }
    }

    // Four parameters
    static public class Messenger<T, U, V, W>
    {
        private static Dictionary<string, Delegate> eventTable = MessengerInternal.eventTable;

        static public void AddListener(string eventType, Callback<T, U, V, W> handler)
        {
            MessengerInternal.OnListenerAdding(eventType, handler);
            eventTable[eventType] = (Callback<T, U, V, W>)eventTable[eventType] + handler;
        }

        static public void RemoveListener(string eventType, Callback<T, U, V, W> handler)
        {
            MessengerInternal.OnListenerRemoving(eventType, handler);
            eventTable[eventType] = (Callback<T, U, V, W>)eventTable[eventType] - handler;
            MessengerInternal.OnListenerRemoved(eventType);
        }

        static public void Broadcast(string eventType, T arg1, U arg2, V arg3, W arg4)
        {
            Broadcast(eventType, arg1, arg2, arg3, arg4, MessengerInternal.DEFAULT_MODE);
        }

        static public void Broadcast(string eventType, T arg1, U arg2, V arg3, W arg4, MessengerMode mode)
        {
            MessengerInternal.OnBroadcasting(eventType, mode);
            Delegate d;
            if (eventTable.TryGetValue(eventType, out d))
            {
                Callback<T, U, V, W> callback = d as Callback<T, U, V, W>;
                if (callback != null)
                {
                    callback(arg1, arg2, arg3, arg4);
                }
                else
                {
                    throw MessengerInternal.CreateBroadcastSignatureException(eventType);
                }
            }
        }
    }

    // Five parameters
    static public class Messenger<T, U, V, W, X>
    {
        private static Dictionary<string, Delegate> eventTable = MessengerInternal.eventTable;

        static public void AddListener(string eventType, Callback<T, U, V, W, X> handler)
        {
            MessengerInternal.OnListenerAdding(eventType, handler);
            eventTable[eventType] = (Callback<T, U, V, W, X>)eventTable[eventType] + handler;
        }

        static public void RemoveListener(string eventType, Callback<T, U, V, W, X> handler)
        {
            MessengerInternal.OnListenerRemoving(eventType, handler);
            eventTable[eventType] = (Callback<T, U, V, W, X>)eventTable[eventType] - handler;
            MessengerInternal.OnListenerRemoved(eventType);
        }

        static public void Broadcast(string eventType, T arg1, U arg2, V arg3, W arg4, X arg5)
        {
            Broadcast(eventType, arg1, arg2, arg3, arg4, arg5, MessengerInternal.DEFAULT_MODE);
        }

        static public void Broadcast(string eventType, T arg1, U arg2, V arg3, W arg4, X arg5, MessengerMode mode)
        {
            MessengerInternal.OnBroadcasting(eventType, mode);
            Delegate d;
            if (eventTable.TryGetValue(eventType, out d))
            {
                Callback<T, U, V, W, X> callback = d as Callback<T, U, V, W, X>;
                if (callback != null)
                {
                    callback(arg1, arg2, arg3, arg4, arg5);
                }
                else
                {
                    throw MessengerInternal.CreateBroadcastSignatureException(eventType);
                }
            }
        }
    }

    // Six parameters
    static public class Messenger<T, U, V, W, X, Y>
    {
        private static Dictionary<string, Delegate> eventTable = MessengerInternal.eventTable;

        static public void AddListener(string eventType, Callback<T, U, V, W, X, Y> handler)
        {
            MessengerInternal.OnListenerAdding(eventType, handler);
            eventTable[eventType] = (Callback<T, U, V, W, X, Y>)eventTable[eventType] + handler;
        }

        static public void RemoveListener(string eventType, Callback<T, U, V, W, X, Y> handler)
        {
            MessengerInternal.OnListenerRemoving(eventType, handler);
            eventTable[eventType] = (Callback<T, U, V, W, X, Y>)eventTable[eventType] - handler;
            MessengerInternal.OnListenerRemoved(eventType);
        }

        static public void Broadcast(string eventType, T arg1, U arg2, V arg3, W arg4, X arg5, Y arg6)
        {
            Broadcast(eventType, arg1, arg2, arg3, arg4, arg5, arg6, MessengerInternal.DEFAULT_MODE);
        }

        static public void Broadcast(string eventType, T arg1, U arg2, V arg3, W arg4, X arg5, Y arg6, MessengerMode mode)
        {
            MessengerInternal.OnBroadcasting(eventType, mode);
            Delegate d;
            if (eventTable.TryGetValue(eventType, out d))
            {
                Callback<T, U, V, W, X, Y> callback = d as Callback<T, U, V, W, X, Y>;
                if (callback != null)
                {
                    callback(arg1, arg2, arg3, arg4, arg5, arg6);
                }
                else
                {
                    throw MessengerInternal.CreateBroadcastSignatureException(eventType);
                }
            }
        }
    }
}

// MessengerUnitTest.cs v1.0 by Magnus Wolffelt, magnus.wolffelt@gmail.com
//
// Delegates used in Messenger.cs.
namespace Common.Messenger
{
    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);
    public delegate void Callback<T, U, V, W>(T arg1, U arg2, V arg3, W arg4);
    public delegate void Callback<T, U, V, W, X>(T arg1, U arg2, V arg3, W arg4, X arg5);
    public delegate void Callback<T, U, V, W, X, Y>(T arg1, U arg2, V arg3, W arg4, X arg5, Y arg6);

    public delegate T CallbackReturn<T>();
    public delegate T CallbackReturn<T, U>(U arg1);
}

namespace Common.Messenger
{
    /// <summary>
    /// This class is used to define all eventId.
    /// Event string must be different.
    /// </summary>
    public class MessengerEventDef
    {

    }
}

转载请注明出处：https://www.cnblogs.com/jietian331/p/11003386.html