Unity3D架构系列之FSM有限状态机设计（五）

在设计五中，我们把事件系统EventSystem实现一下。这个EventSystem类主要实现的是事件的注册，触发，以及分发Event消息的作用。提供接口对外使用的。在这里面为了功能扩展方便用了好多模板函数，方便大家调用。

分发消息的时候，我们采用的是队列的方式，就是先进先出原则。

首先要把消息事件注册一下，就是将其放到我们预先定义的表里面。函数代码如下所示：

int Register(string eventName, Func<object,object,object,bool> action) {

   int   listenID = ++mNextListenID;

   Listen  listen = (mFreeListen.Count == 0) ? new Listen() : mFreeListen.Pop();

   listen.mID = listenID;

   listen.mAction = action;

   mRegistered.Add(listenID, listen);

   List<int>  eventList;

   if(!mRegisteredEvents.TryGetValue(eventName, out eventList))

    eventList = mRegisteredEvents[eventName] = new List<int>();

   eventList.Add(listenID);

   return listenID;

  }

接下来就是 消息事件的触发代码如下：

  public void Trigger(string eventName) {

   Call(eventName, null, null, null);

  }

void Call(string eventName, object arg1, object arg2, object arg3) {

   List<int> listenerList;

   if(mRegisteredEvents.TryGetValue(eventName, out listenerList)) {

    for(int i = listenerList.Count - 1; i >= 0; --i) {

     Listen listener;

     if(mRegistered.TryGetValue(listenerList[i], out listener)) {

      if(!listener.mAction(arg1, arg2, arg3)) {

       mRegistered.Remove(listenerList[i]);

       mFreeListen.Push(listener);

       listenerList.RemoveAt(i);

      }

     }

     else {

      listenerList.RemoveAt(i);

     }

    }

    if(listenerList.Count == 0) {

     mRegisteredEvents.Remove(eventName);

    }

   }

  }

 遍历查找消息列表是否在mRegistererdEvents这个字典里面，mRegisteredEvents的定义如下：

Dictionary<string,List<int>>  mRegisteredEvents = new Dictionary<string, List<int>>();

  Listen的定义如下：

  class Listen {

   public int        mID;

   public Func<object,object,object,bool> mAction;

  }

 接下来就是最核心的功能了，状态机的切换功能代码：

public int On(string eventName, Funcbool> action) {

   return Register(eventName, delegate(object arg1, object arg2, object arg3) {

    T1  param1;

    T2  param2;

    T3  param3;

    try { param1 = (T1)arg1; } catch { param1 = default(T1); }

    try { param2 = (T2)arg2; } catch { param2 = default(T2); }

    try { param3 = (T3)arg3; } catch { param3 = default(T3); }

    return(action(param1, param2, param3));

   });

  }



  public int On(string eventName, Action action) {

   return Register(eventName, delegate(object arg1, object arg2, object arg3) {

    T1  param1;

    T2  param2;

    T3  param3;

    try { param1 = (T1)arg1; } catch { param1 = default(T1); }

    try { param2 = (T2)arg2; } catch { param2 = default(T2); }

    try { param3 = (T3)arg3; } catch { param3 = default(T3); }

    action(param1, param2, param3);

    return true;

   });

  }

整个的EventSystem事件系统的代码如下所示：

using System;
using System.Collections;
using System.Collections.Generic;
namespace EventSystem {
 public class Dispatcher {
  public void Trigger(string eventName) {
   Call(eventName, null, null, null);
  }

  public void Dispatch(string eventName) {
   Dispatched d = (mFreeDispatch.Count == 0) ? new Dispatched() : mFreeDispatch.Pop();
   mDispatched.Enqueue(d.Set(eventName));
  }

  public int On(string eventName, Func<bool> action) {
   return Register(eventName, delegate(object arg1, object arg2, object arg3) {
    return(action());
   });
  }

  public int On(string eventName, Action action) {
   return Register(eventName, delegate(object arg1, object arg2, object arg3) {
    action();
    return(true);
   });
  }

  public void Trigger(string eventName, object param1) {
   Call(eventName, param1, null, null);
  }

  public void Dispatch(string eventName, object param1) {
   Dispatched d = (mFreeDispatch.Count == 0) ? new Dispatched() : mFreeDispatch.Pop();
   mDispatched.Enqueue(d.Set(eventName, param1));
  }

  public int On(string eventName, Funcbool> action) {
   return Register(eventName, delegate(object arg1, object arg2, object arg3) {
    T  param1;
    try { param1 = (T)arg1; } catch { param1 = default(T); }
    return(action(param1));
   });
  }

  public int On(string eventName, Action action) {
   return Register(eventName, delegate(object arg1, object arg2, object arg3) {
    T  param1;
    try { param1 = (T)arg1; } catch { param1 = default(T); }
    action(param1);
    return true;
   });
  }

  public void Trigger(string eventName, object param1, object param2) {
   Call(eventName, param1, param2, null);
  }

  public void Dispatch(string eventName, object param1, object param2) {
   Dispatched d = (mFreeDispatch.Count == 0) ? new Dispatched() : mFreeDispatch.Pop();
   mDispatched.Enqueue(d.Set(eventName, param1, param2));
  }

  public int On(string eventName, Funcbool> action) {
   return Register(eventName, delegate(object arg1, object arg2, object arg3) {
    T1  param1;
    T2  param2;
    try { param1 = (T1)arg1; } catch { param1 = default(T1); }
    try { param2 = (T2)arg2; } catch { param2 = default(T2); }
    return(action(param1, param2));
   });
  }

  public int On(string eventName, Action action) {
   return Register(eventName, delegate(object arg1, object arg2, object arg3) {
    T1  param1;
    T2  param2;
    try { param1 = (T1)arg1; } catch { param1 = default(T1); }
    try { param2 = (T2)arg2; } catch { param2 = default(T2); }
    action(param1, param2);
    return true;
   });
  }

  public void Trigger(string eventName, object param1, object param2, object param3) {
   Call(eventName, param1, param2, param3);
  }

  public void Dispatch(string eventName, object param1, object param2, object param3){
   Dispatched d = (mFreeDispatch.Count == 0) ? new Dispatched() : mFreeDispatch.Pop();
   mDispatched.Enqueue(d.Set(eventName, param1, param2, param3));
  }

  public int On(string eventName, Funcbool> action) {
   return Register(eventName, delegate(object arg1, object arg2, object arg3) {
    T1  param1;
    T2  param2;
    T3  param3;
    try { param1 = (T1)arg1; } catch { param1 = default(T1); }
    try { param2 = (T2)arg2; } catch { param2 = default(T2); }
    try { param3 = (T3)arg3; } catch { param3 = default(T3); }
    return(action(param1, param2, param3));
   });
  }

  public int On(string eventName, Action action) {
   return Register(eventName, delegate(object arg1, object arg2, object arg3) {
    T1  param1;
    T2  param2;
    T3  param3;
    try { param1 = (T1)arg1; } catch { param1 = default(T1); }
    try { param2 = (T2)arg2; } catch { param2 = default(T2); }
    try { param3 = (T3)arg3; } catch { param3 = default(T3); }
    action(param1, param2, param3);
    return true;
   });
  }

  public bool Cancel(int listenerID) {
   return mRegistered.Remove(listenerID);
  }

  public void DispatchPending() {
   while(mDispatched.Count > 0) {
    Dispatched d = mDispatched.Dequeue();
    Call(d.mEventName, d.mArg1, d.mArg2, d.mArg3);
    mFreeDispatch.Push(d);
   }
  }

  int Register(string eventName, Func<object,object,object,bool> action) {
   int   listenID = ++mNextListenID;
   Listen  listen = (mFreeListen.Count == 0) ? new Listen() : mFreeListen.Pop();
   listen.mID = listenID;
   listen.mAction = action;
   mRegistered.Add(listenID, listen);
   List<int>  eventList;
   if(!mRegisteredEvents.TryGetValue(eventName, out eventList))
    eventList = mRegisteredEvents[eventName] = new List<int>();
   eventList.Add(listenID);
   return listenID;
  }

  void Call(string eventName, object arg1, object arg2, object arg3) {
   List<int> listenerList;
   if(mRegisteredEvents.TryGetValue(eventName, out listenerList)) {
    for(int i = listenerList.Count - 1; i >= 0; --i) {
     Listen listener;
     if(mRegistered.TryGetValue(listenerList[i], out listener)) {
      if(!listener.mAction(arg1, arg2, arg3)) {
       mRegistered.Remove(listenerList[i]);
       mFreeListen.Push(listener);
       listenerList.RemoveAt(i);
      }
     }
     else {
      listenerList.RemoveAt(i);
     }
    }
    if(listenerList.Count == 0) {
     mRegisteredEvents.Remove(eventName);
    }
   }
  }

  class Listen {
   public int        mID;
   public Func<object,object,object,bool> mAction;
  }

  class Dispatched {
   public Dispatched Set(string eventName, object arg1=null, object arg2=null, object arg3=null) {
    mEventName = eventName;
    mArg1 = arg1;
    mArg2 = arg2;
    mArg3 = arg3;
    return this;
   }
   public string mEventName;
   public object mArg1, mArg2, mArg3;
  }

  Dictionary<string,List<int>>  mRegisteredEvents = new Dictionary<string, List<int>>();
  Dictionary<int,Listen>    mRegistered = new Dictionary<int, Listen>();
  Stack      mFreeListen = new Stack();
  Stack     mFreeDispatch = new Stack();
  Queue     mDispatched = new Queue();
  int         mNextListenID = 4711;
 }
}

接下来我会在最后一讲也就是设计六中，给大家说一下如何去使用。

转自：http://jxwgame.blog.51cto.com/943299/1613585