Unity3d事件的监听与广播系统

个人学习笔记

来源01：siki学院“Unity3d事件的监听与广播系统”

方式一 siki学院采用委托

消息类型     枚举

public enum EventType
{
    ShowText,
}

回调函数  委托  相当于Action

public delegate void CallBack();
public delegate void CallBack<T>(T arg);
public delegate void CallBack<T, X>(T arg1, X arg2);
public delegate void CallBack<T, X, Y>(T arg1, X arg2, Y arg3);
public delegate void CallBack<T, X, Y, Z>(T arg1, X arg2, Y arg3, Z arg4);
public delegate void CallBack<T, X, Y, Z, W>(T arg1, X arg2, Y arg3, Z arg4, W arg5);

 消息事件的基类   初始化消息 消息底层实现（添加、移除、回调）

笔记：

使用Dictionary存放 消息类型（Key）,委托（Value）；

添加、移除即向Dictionary中添加、删除键、值；

广播（Broadcast）：传入消息类型（key）,在Dictionary获得对应的委托（Value）,然后回调。

（由于委托能包装的方法有一定限制：方法的签名必须与委托一致，方法签名包括参数的个数、类型和顺序，，所以扩展比较麻烦），则每个回调（委托）都要重新封装一个函数

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class EventCenter
{
    private static Dictionary<EventType, Delegate> m_EventTable = new Dictionary<EventType, Delegate>();

    private static void OnListenerAdding(EventType eventType, Delegate callBack)
    {
        if (!m_EventTable.ContainsKey(eventType))
        {
            m_EventTable.Add(eventType, null);
        }
        Delegate d = m_EventTable[eventType];
        if (d != null && d.GetType() != callBack.GetType())
        {
            throw new Exception(string.Format("尝试为事件{0}添加不同类型的委托，当前事件所对应的委托是{1}，要添加的委托类型为{2}", eventType, d.GetType(), callBack.GetType()));
        }
    }
    private static void OnListenerRemoving(EventType eventType, Delegate callBack)
    {
        if (m_EventTable.ContainsKey(eventType))
        {
            Delegate d = m_EventTable[eventType];
            if (d == null)
            {
                throw new Exception(string.Format("移除监听错误：事件{0}没有对应的委托", eventType));
            }
            else if (d.GetType() != callBack.GetType())
            {
                throw new Exception(string.Format("移除监听错误：尝试为事件{0}移除不同类型的委托，当前委托类型为{1}，要移除的委托类型为{2}", eventType, d.GetType(), callBack.GetType()));
            }
        }
        else
        {
            throw new Exception(string.Format("移除监听错误：没有事件码{0}", eventType));
        }
    }
    private static void OnListenerRemoved(EventType eventType)
    {
        if (m_EventTable[eventType] == null)
        {
            m_EventTable.Remove(eventType);
        }
    }
    //no parameters
    public static void AddListener(EventType eventType, CallBack callBack)
    {
        OnListenerAdding(eventType, callBack);
        m_EventTable[eventType] = (CallBack)m_EventTable[eventType] + callBack;
    }
    //Single parameters
    public static void AddListener<T>(EventType eventType, CallBack<T> callBack)
    {
        OnListenerAdding(eventType, callBack);
        m_EventTable[eventType] = (CallBack<T>)m_EventTable[eventType] + callBack;
    }
    //two parameters
    public static void AddListener<T, X>(EventType eventType, CallBack<T, X> callBack)
    {
        OnListenerAdding(eventType, callBack);
        m_EventTable[eventType] = (CallBack<T, X>)m_EventTable[eventType] + callBack;
    }
    //three parameters
    public static void AddListener<T, X, Y>(EventType eventType, CallBack<T, X, Y> callBack)
    {
        OnListenerAdding(eventType, callBack);
        m_EventTable[eventType] = (CallBack<T, X, Y>)m_EventTable[eventType] + callBack;
    }
    //four parameters
    public static void AddListener<T, X, Y, Z>(EventType eventType, CallBack<T, X, Y, Z> callBack)
    {
        OnListenerAdding(eventType, callBack);
        m_EventTable[eventType] = (CallBack<T, X, Y, Z>)m_EventTable[eventType] + callBack;
    }
    //five parameters
    public static void AddListener<T, X, Y, Z, W>(EventType eventType, CallBack<T, X, Y, Z, W> callBack)
    {
        OnListenerAdding(eventType, callBack);
        m_EventTable[eventType] = (CallBack<T, X, Y, Z, W>)m_EventTable[eventType] + callBack;
    }

    //no parameters
    public static void RemoveListener(EventType eventType, CallBack callBack)
    {
        OnListenerRemoving(eventType, callBack);
        m_EventTable[eventType] = (CallBack)m_EventTable[eventType] - callBack;
        OnListenerRemoved(eventType);
    }
    //single parameters
    public static void RemoveListener<T>(EventType eventType, CallBack<T> callBack)
    {
        OnListenerRemoving(eventType, callBack);
        m_EventTable[eventType] = (CallBack<T>)m_EventTable[eventType] - callBack;
        OnListenerRemoved(eventType);
    }
    //two parameters
    public static void RemoveListener<T, X>(EventType eventType, CallBack<T, X> callBack)
    {
        OnListenerRemoving(eventType, callBack);
        m_EventTable[eventType] = (CallBack<T, X>)m_EventTable[eventType] - callBack;
        OnListenerRemoved(eventType);
    }
    //three parameters
    public static void RemoveListener<T, X, Y>(EventType eventType, CallBack<T, X, Y> callBack)
    {
        OnListenerRemoving(eventType, callBack);
        m_EventTable[eventType] = (CallBack<T, X, Y>)m_EventTable[eventType] - callBack;
        OnListenerRemoved(eventType);
    }
    //four parameters
    public static void RemoveListener<T, X, Y, Z>(EventType eventType, CallBack<T, X, Y, Z> callBack)
    {
        OnListenerRemoving(eventType, callBack);
        m_EventTable[eventType] = (CallBack<T, X, Y, Z>)m_EventTable[eventType] - callBack;
        OnListenerRemoved(eventType);
    }
    //five parameters
    public static void RemoveListener<T, X, Y, Z, W>(EventType eventType, CallBack<T, X, Y, Z, W> callBack)
    {
        OnListenerRemoving(eventType, callBack);
        m_EventTable[eventType] = (CallBack<T, X, Y, Z, W>)m_EventTable[eventType] - callBack;
        OnListenerRemoved(eventType);
    }


    //no parameters
    public static void Broadcast(EventType eventType)
    {
        Delegate d;
        if (m_EventTable.TryGetValue(eventType, out d))
        {
            CallBack callBack = d as CallBack;
            if (callBack != null)
            {
                callBack();
            }
            else
            {
                throw new Exception(string.Format("广播事件错误：事件{0}对应委托具有不同的类型", eventType));
            }
        }
    }
    //single parameters
    public static void Broadcast<T>(EventType eventType, T arg)
    {
        Delegate d;
        if (m_EventTable.TryGetValue(eventType, out d))
        {
            CallBack<T> callBack = d as CallBack<T>;
            if (callBack != null)
            {
                callBack(arg);
            }
            else
            {
                throw new Exception(string.Format("广播事件错误：事件{0}对应委托具有不同的类型", eventType));
            }
        }
    }
    //two parameters
    public static void Broadcast<T, X>(EventType eventType, T arg1, X arg2)
    {
        Delegate d;
        if (m_EventTable.TryGetValue(eventType, out d))
        {
            CallBack<T, X> callBack = d as CallBack<T, X>;
            if (callBack != null)
            {
                callBack(arg1, arg2);
            }
            else
            {
                throw new Exception(string.Format("广播事件错误：事件{0}对应委托具有不同的类型", eventType));
            }
        }
    }
    //three parameters
    public static void Broadcast<T, X, Y>(EventType eventType, T arg1, X arg2, Y arg3)
    {
        Delegate d;
        if (m_EventTable.TryGetValue(eventType, out d))
        {
            CallBack<T, X, Y> callBack = d as CallBack<T, X, Y>;
            if (callBack != null)
            {
                callBack(arg1, arg2, arg3);
            }
            else
            {
                throw new Exception(string.Format("广播事件错误：事件{0}对应委托具有不同的类型", eventType));
            }
        }
    }
    //four parameters
    public static void Broadcast<T, X, Y, Z>(EventType eventType, T arg1, X arg2, Y arg3, Z arg4)
    {
        Delegate d;
        if (m_EventTable.TryGetValue(eventType, out d))
        {
            CallBack<T, X, Y, Z> callBack = d as CallBack<T, X, Y, Z>;
            if (callBack != null)
            {
                callBack(arg1, arg2, arg3, arg4);
            }
            else
            {
                throw new Exception(string.Format("广播事件错误：事件{0}对应委托具有不同的类型", eventType));
            }
        }
    }
    //five parameters
    public static void Broadcast<T, X, Y, Z, W>(EventType eventType, T arg1, X arg2, Y arg3, Z arg4, W arg5)
    {
        Delegate d;
        if (m_EventTable.TryGetValue(eventType, out d))
        {
            CallBack<T, X, Y, Z, W> callBack = d as CallBack<T, X, Y, Z, W>;
            if (callBack != null)
            {
                callBack(arg1, arg2, arg3, arg4, arg5);
            }
            else
            {
                throw new Exception(string.Format("广播事件错误：事件{0}对应委托具有不同的类型", eventType));
            }
        }
    }
}

 案例使用：点击按钮，Text显示

创建Button脚本挂载在Button上面

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class sikiButton : MonoBehaviour {

    private void Awake()
    {
        GetComponent<Button>().onClick.AddListener(() =>
        {
            //事件广播
            EventCenter.Broadcast(EventType.ShowText);
        } );
    }
}

 创建Text脚本挂载在Text上面

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class sikiText : MonoBehaviour {

    private void Awake()
    {
        gameObject.SetActive(false);
        EventCenter.AddListener(EventType.ShowText,Show);
    }
    private void OnDestroy()
    {
        EventCenter.RemoveListener(EventType.ShowText,Show);
    }
    private void Show()
    {
        gameObject.SetActive(true);
    }
}