Unity简易事件触发器

事件触发器作为unity常用的模块解耦工具，其主要功能有三点:

1. 订阅事件
2. 移除事件
3. 事件触发，并传给监听的回调方法

之前在网上看了很多帖子，通常是用一个消息体对象作为回调参数，但是我个人还是比较喜欢使用泛型的方式进行回调，参考了之前项目的工具类，便动手开始实现。话不多说，先上代码：

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

public class ObserverEvents
{
  Dictionary<string, ArrayList> actions = null;
  /// <summary>
  /// 订阅
  /// </summary>
  public void Subscribe(string eventName, object action)
  {
    if (actions == null)
      actions = new Dictionary<string, ArrayList>();
    ArrayList callback;
    if (actions.TryGetValue(eventName, out callback))
    {
      if (!callback.Contains(action))
        callback.Add(action);
    }
    else
    {
      callback = new ArrayList();
      callback.Add(action);
      actions[eventName] = callback;
    }
  }
  /// <summary>
  /// 注销整个事件
  /// </summary>
  public void Unsubscribe(string eventName)
  {
    if (actions == null) return;
    ArrayList callback;
    if (actions.TryGetValue(eventName, out callback))
    {
      callback.Clear();
      actions.Remove(eventName);
    }
  }
  /// <summary>
  /// 注销某一事件中的单个回调
  /// </summary>
  /// <param name="eventName"></param>
  /// <param name="action"></param>
  public void Unsubscribe(string eventName, object action)
  {
    if (actions == null) return;
    ArrayList callback;
    if (actions.TryGetValue(eventName, out callback))
    {
      if (callback.Contains(action))
      {
        callback.Remove(action);
        if (callback.Count == 0)
          actions.Remove(eventName);
      }
    }
  }

  public ArrayList GetActions(string eventName)
  {
    if (actions == null) return null;
    ArrayList callBack;
    if (actions.TryGetValue(eventName, out callBack))
      return callBack;
    return null;
  }

}

ObserverEvents事件容器类，用于存储参数个数一样的不同事件

using System;
using System.Collections;
using System.Collections.Generic;
/// <summary>
/// 事件触发器
/// </summary>
public class EventDispather 
: Singleton //注释：这里其实是Singleton<EventDispather> 但是简书上Singleton后面加上'<>'就没有高亮了，不懂，有哪位兄弟能告诉一下吗？
{
  private EventDispather() { }
  /// <summary>
  /// 创建参数个数不同的事件容器
  /// </summary>
  private ObserverEvents events = new ObserverEvents();
  private ObserverEvents eventsT1 = new ObserverEvents();
  private ObserverEvents eventsT2 = new ObserverEvents();
  private ObserverEvents eventsT3 = new ObserverEvents();
  
  #region 事件的订阅
  public void SubscribeEvent(string eventName, Action<string> act)
  {
    events.Subscribe(eventName, act);
  }
  public void SubscribeEvent<T>(string eventName, Action<string, T> act)
  {
    eventsT1.Subscribe(eventName, act);
  }
  public void SubscribeEvent<T1, T2>(string eventName, Action<string, T1, T2> act)
  {
    eventsT2.Subscribe(eventName, act);
  }
  public void SubscribeEvent<T1, T2, T3>(string eventName, Action<string, T1, T2, T3> act)
  {
    eventsT3.Subscribe(eventName, act);
  }
  #endregion
  
  #region 注销事件
  public void Unsubscribe(string eventName, Action<string> act)
  {
    events.Unsubscribe(eventName, act);
  }
  public void Unsubscribe<T>(string eventName, Action<string, T> act)
  {
    eventsT1.Unsubscribe(eventName, act);
  }
  public void Unsubscribe<T1, T2>(string eventName, Action<string, T1, T2> act)
  {
    eventsT2.Unsubscribe(eventName, act);
  }
  public void Unsubscribe<T1, T2, T3>(string eventName, Action<string, T1, T2, T3> act)
  {
    eventsT3.Unsubscribe(eventName, act);
  }

  public void RemoveEvent(string eventName)
  {
    events.Unsubscribe(eventName);
    eventsT1.Unsubscribe(eventName);
    eventsT2.Unsubscribe(eventName);
    eventsT3.Unsubscribe(eventName);
  }
  #endregion
  
  #region 事件触发
  public void PostEvent(string eventNme)
  {
    var actions = events.GetActions(eventNme);
    if (actions != null)
    {
      for (int i = actions.Count - 1; i >= 0; i--)
      {
        var action = actions[i];
        if (action == null)
          actions.Remove(action);
        else
        {
          var act = action as Action<string>;
          if (act != null)
            act(eventNme);
        }
      }
    }
  }
  public void PostEvent<T>(string eventNme, T param)
  {
    var actions = eventsT1.GetActions(eventNme);
    if (actions != null)
    {
      for (int i = actions.Count - 1; i >= 0; i--)
      {
        var action = actions[i];
        if (action == null)
          actions.Remove(action);
        else
        {
          var act = action as Action<string, T>;
          if (act != null)
            act(eventNme, param);
        }
      }
    }
  }
  public void PostEvent<T1, T2>(string eventNme, T1 param1, T2 param2)
  {
    var actions = events.GetActions(eventNme);
    if (actions != null)
    {
      for (int i = actions.Count - 1; i >= 0; i--)
      {
        var action = actions[i];
        if (action == null)
          actions.Remove(action);
        else
        {
          var act = action as Action<string, T1, T2>;
          if (act != null)
            act(eventNme, param1, param2);
        }
      }
    }
  }
  public void PostEvent<T1, T2, T3>(string eventNme, T1 param1, T2 param2, T3 param3)
  {
    var actions = events.GetActions(eventNme);
    if (actions != null)
    {
      for (int i = actions.Count - 1; i >= 0; i--)
      {
        var action = actions[i];
        if (action == null)
          actions.Remove(action);
        else
        {
          var act = action as Action<string, T1, T2, T3>;
          if (act != null)
            act(eventNme, param1, param2, param3);
        }
      }
    }
  }
  #endregion
  
}

EventDispather使用单例模板，具体实现请看之前的分享。

EventDispather内部创建了4个ObserverEvents事件容器，分别对应无参和至多3个参数的事件(PS:如果想更多参数的可以自行扩展)，然后根据对应的事件进行注册、查找与回调

测试代码

    string event_name = "test";
    Action<string> act0 = (name) =>
    {
      Debug.Log(name);
    };
    Action<string, string> act1 = (name, content) =>
     {
       Debug.Log(name + "   string:   " + content);
     };
    Action<string, int> act2 = (name, num) =>
     {
       Debug.Log(name + "   num:   " + num);
     };
    //注册事件
    EventDispather.Instance.SubscribeEvent(event_name, act0);
    EventDispather.Instance.SubscribeEvent<string>(event_name, act1);
    EventDispather.Instance.SubscribeEvent<int>(event_name, act2);
    //事件提交
    EventDispather.Instance.PostEvent(event_name);
    EventDispather.Instance.PostEvent<string>(event_name, "你好");
    EventDispather.Instance.PostEvent<int>(event_name, 521);
    //注销事件
    EventDispather.Instance.Unsubscribe(event_name, act0);
    EventDispather.Instance.Unsubscribe<string>(event_name, act1);
    EventDispather.Instance.Unsubscribe<int>(event_name, act2);

测试结果

test
test   string:   你好
test   num:   521

是不是感觉很easy~

但是对于我们程序员来说不只是要掌握更多的记住，更要能够温故知新，只有每天不断的学习才不会原地踏步，被世界远远的甩在身后。

最后送上我喜欢的一句话：

放弃并不难，但坚持一定很酷 ！