本人一直認為AS3的事件處理機制很是給力 , 今天鼓搗了出來并完美得通過了測試。在AS3中使用函數addEventListener添加事件偵聽,用removeEventListener移除事件偵聽。著用封裝的一個類庫可以徹底地終結消息傳遞中無規則,無規律的混亂狀態,從而達到代碼邏輯清晰性。改起來也相當簡單(做過程序員的都懂)。
關于此類庫的實現原理 , 其實使用的是委托(delegate),讓偵聽函數(觀察者)掛載到此委托上,當然消息有不同的類型,如windows系統中有單擊,雙擊,右擊等不同的事件類型,在這個類庫里面都有實現。
首先,需要指出:
IEventType ( 所有事件類型的接口 )
using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace MsgEventLib.com { public interface IEventType { /// <summary> /// 類的類型 /// </summary> Type EventMainType { get; } String GetEventTypeName(string type); } }
思想:事件類型以 類的Type.Name + "_" + 事件名稱 。 以GetEventTypeName方法實現。
傳遞的消息體:
using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace MsgEventLib.com { public class BaseEvent { public BaseEvent(string eventType, object sender, object msg) { this.eventType = eventType; this.sender = sender; this.msg = msg; } private string @eventType; public string EventType { set { this.eventType = value; } get { return this.eventType; } } private object @sender; public Object Sender { set { this.sender = value; } get { return this.sender; } } private object @msg; public object Msg { set { this.msg = value; } get { return this.msg; } } } }
其中:eventType為事件類型名稱 GetEventTypeName , Sender為發送者 , Msg為消息體
事件偵聽管理器的實現
using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace MsgEventLib.com { public sealed class EventListener : IEventListener { private static IEventListener @instance; public static IEventListener Instance { get { if (instance == null) instance = new EventListener(); return instance; } } private Dictionary<string, DeListener> @listeners; private EventListener() { @listeners = new Dictionary<string, DeListener>(); } public void AddEventListener(string type, DeListener myListener) { if (!@listeners.ContainsKey(type)) @listeners.Add(type, myListener); else @listeners[type] += myListener; } public void RemoveEventListener(string type, DeListener myListener) { if (@listeners.ContainsKey(type)) { @listeners[type] -= myListener; if (@listeners[type] == null) @listeners.Remove(type); } } public void RemoveAllEventListener() { if (@listeners != null && @listeners.Count > 0) { List<string> keys = new List<string>(@listeners.Keys);//獲得所有的鍵值 for (int j = 0; j < keys.Count; j++) { if (@listeners[keys[j]] != null) { Delegate[] des = @listeners[keys[j]].GetInvocationList(); if (des != null && des.Length > 0) { for (int i = 0; i < des.Length; i++) { @listeners[keys[j]] -= des[i] as DeListener; } } } @listeners.Remove(keys[j]); } } } public DeListener GetDeListenerByType(string type) { if (@listeners != null && @listeners.ContainsKey(type)) { return @listeners[type]; } return null; } public void Destory() { this.RemoveAllEventListener(); if (@instance != null) @instance = null; } } }
值得注意的是 , 字典 : key為事件類型(GetEventTypeName) , value為委托(可能有多個掛載/觀察者)
關于事件發送者(主題)
using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace MsgEventLib.com { public sealed class EventDispacterManager : IEventDispacterManager { private static IEventDispacterManager @instance; public static IEventDispacterManager Instance { get { if (instance == null) instance = new EventDispacterManager(); return instance; } } public void Dispatch(string type , BaseEvent @myevent) { DeListener target = EventListener.Instance.GetDeListenerByType(type); if (target != null) { target(@myevent); } } } }
測試的結果
1 , 事件類型
using System; using System.Collections.Generic; using System.Linq; using System.Text; using MsgEventLib.com; namespace TestA.com { public class MyEventType : IEventType { private static MyEventType @instance; public static MyEventType Instance { get { if (@instance == null) @instance = new MyEventType(); return @instance; } } public Type EventMainType { get { return typeof(MyEventType); } } public string GetEventTypeName(string type) { return this.EventMainType.Name + "_" + type; } public static string CLOSE_WINDOWS = "CLOSE_WINDOWS"; public static string OTHRT_TYPE = "OTHRT_TYPE"; } }
2 , 3個類(偵聽著)
①:
using System; using System.Collections.Generic; using System.Linq; using System.Text; using MsgEventLib.com; namespace TestA.com { public sealed class Listeners { public Listeners() { string type = MyEventType.Instance.GetEventTypeName(MyEventType.CLOSE_WINDOWS); EventListener.Instance.AddEventListener(type, this.Li); } private void Li(BaseEvent e) { Console.WriteLine("Listeners 觸發了Event {0} ", e.Msg); } } }
②:
using MsgEventLib.com; using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TestA.com { public sealed class Lis2 { public Lis2() { string type = MyEventType.Instance.GetEventTypeName(MyEventType.CLOSE_WINDOWS); EventListener.Instance.AddEventListener(type, this.Li); } private void Li(BaseEvent e) { Console.WriteLine("Lis2 觸發了Event {0} ", e.Msg); } public void RemoveLis() { string type = MyEventType.Instance.GetEventTypeName(MyEventType.CLOSE_WINDOWS); EventListener.Instance.RemoveEventListener(type, this.Li); Console.WriteLine("Lis2 移除了事件偵聽!"); } } }
③:
using MsgEventLib.com; using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TestA.com { public sealed class Lis3 { public Lis3() { string type = MyEventType.Instance.GetEventTypeName(MyEventType.OTHRT_TYPE); EventListener.Instance.AddEventListener(type, this.Li); } private void Li(BaseEvent e) { Console.WriteLine("Lis3 觸發了Event {0} ", e.Msg); } } }
事件發送者
using System; using System.Collections.Generic; using System.Linq; using System.Text; using MsgEventLib.com; namespace TestA.com { public sealed class Dispatch { public void Dis() { string type = MyEventType.Instance.GetEventTypeName(MyEventType.CLOSE_WINDOWS); EventDispacterManager.Instance.Dispatch(type, new BaseEvent(type, this, "Event_關閉你的窗口")); } } }
測試:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using TestA.com;
namespace TestA
{
public class Program
{
static void Main(string[] args)
{
Dispatch di = new Dispatch();
Listeners li = new Listeners();
Lis2 li2 = new Lis2();
Lis3 li3 = new Lis3();
di.Dis();
li2.RemoveLis();
di.Dis();
Console.Read();
}
}
}
結果:
因為Lis3偵聽的不是事件CLOSE_WINDOWS , 既不會觸發 。 因為Lis2移除了事件,所以第二次不會觸發。
這只是部分大碼。詳細請見附件。
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