任意地方监听同一事件

基本原理：使用同一个事件调度类。调度类可以扩展EventDispatcher，或者直接使用EventDispatcher，或者实现IEventDispatcher。

在flex中中新建一个EventDispatcher对象作为共享对象，用它抛出事件对象，然后在任意需要监听这个事件对象的取得这个共享的EventDispatcher，并添加监听处理函数或方法。

例子1：使用同一父亲的EventDispatcher。EventDispatcher是 DisplayObject 类的基类。

test.mxml

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark"
        xmlns:mx="library://ns.adobe.com/flex/mx"  xmlns:c="customer.*">
 <fx:Script>
  <![CDATA[
   import mx.events.FlexEvent;
   import customer.CustomEvent;

  ]]>
 </fx:Script>
 <s:Group>
  
<s:layout>
 <s:HorizontalLayout />
</s:layout>
 <c:CustomCanvas2 id="main"  height="108" width="168"/>
 <c:CustomCanvas1 id="two"  height="108"/>
 </s:Group>
</s:WindowedApplication>

CustomCanvas2

<?xml version="1.0" encoding="utf-8"?>
<s:Group xmlns:fx="http://ns.adobe.com/mxml/2009"
   xmlns:s="library://ns.adobe.com/flex/spark"
   xmlns:mx="library://ns.adobe.com/flex/mx" width="400" height="300">
 <s:layout>
  <s:BasicLayout/>
 </s:layout>
 <fx:Declarations>
  <!-- 将非可视元素（例如服务、值对象）放在此处 -->
 </fx:Declarations>
 <mx:Canvas width="160" height="100" backgroundColor="#E5E4E4">
  <fx:Script>
   <![CDATA[
   private function clickHandler(event:MouseEvent):void{
   var custom:CustomEvent=new CustomEvent(CustomEvent.EVENT_NAME);
   //custom.data is Object;//发送事件同时，可以传值(可传可不传)
   custom.data=mytxt.text;
   this.parent.dispatchEvent(custom);
   }
   ]]>
  </fx:Script>
  <mx:TextInput id="mytxt" text="CustomEvent Data" width="140" x="10" y="10"/>
  <mx:Button click="clickHandler(event);" label="Send CustomEvent" x="10" y="40"/>
 </mx:Canvas>
</s:Group>

CustomCanvas1

<?xml version="1.0" encoding="utf-8"?>
<s:Group xmlns:fx="http://ns.adobe.com/mxml/2009"
   xmlns:s="library://ns.adobe.com/flex/spark"
   xmlns:mx="library://ns.adobe.com/flex/mx" width="400" height="300" creationComplete="init();">
 <s:layout>
  <s:BasicLayout/>
 </s:layout>
 <fx:Declarations>
  <!-- 将非可视元素（例如服务、值对象）放在此处 -->
 </fx:Declarations>
 <mx:Canvas  width="150" height="100" backgroundColor="#E5E4E4">
  <fx:Script>
   <![CDATA[
   import mx.controls.Alert;
   private function init():void{
   this.parent.addEventListener(CustomEvent.EVENT_NAME,clickHandler);
   }
   private function clickHandler(event:CustomEvent):void{
   trace("I get it !");
   mylb.text=event.data.toString();
   Alert.show(event.toString()+"\n"+event.data.toString())
   }
   ]]>
  </fx:Script>
  <mx:TextArea id="mylb" x="10" y="10" width="130" height="80"/>
 </mx:Canvas>
</s:Group>

 

方法2：

test.mxml

同上

CustomCanvas1

<?xml version="1.0" encoding="utf-8"?>
<s:Group xmlns:fx="http://ns.adobe.com/mxml/2009"
   xmlns:s="library://ns.adobe.com/flex/spark"
   xmlns:mx="library://ns.adobe.com/flex/mx" width="400" height="300" creationComplete="init();">
 <s:layout>
  <s:BasicLayout/>
 </s:layout>
 <fx:Declarations>
  <!-- 将非可视元素（例如服务、值对象）放在此处 -->
 </fx:Declarations>
 <mx:Canvas  width="150" height="100" backgroundColor="#E5E4E4">
  <fx:Script>
   <![CDATA[
   import mx.controls.Alert;
   private function init():void{
   CustomEvent.dispatcher.addEventListener(CustomEvent.EVENT_NAME,clickHandler);
   }
   private function clickHandler(event:CustomEvent):void{
   trace("I get it !");
   mylb.text=event.data.toString();
   Alert.show(event.toString()+"\n"+event.data.toString())
   }
   ]]>
  </fx:Script>
  <mx:TextArea id="mylb" x="10" y="10" width="130" height="80"/>
 </mx:Canvas>
</s:Group>

CustomCanvas2

<?xml version="1.0" encoding="utf-8"?>
<s:Group xmlns:fx="http://ns.adobe.com/mxml/2009"
   xmlns:s="library://ns.adobe.com/flex/spark"
   xmlns:mx="library://ns.adobe.com/flex/mx" width="400" height="300">
 <s:layout>
  <s:BasicLayout/>
 </s:layout>
 <fx:Declarations>
  <!-- 将非可视元素（例如服务、值对象）放在此处 -->
 </fx:Declarations>
 <mx:Canvas width="160" height="100" backgroundColor="#E5E4E4">
  <fx:Script>
   <![CDATA[
   private function clickHandler(event:MouseEvent):void{
   var custom:CustomEvent=new CustomEvent(CustomEvent.EVENT_NAME);
   //custom.data is Object;//发送事件同时，可以传值(可传可不传)
   custom.data=mytxt.text;
   CustomEvent.dispatcher.dispatchEvent(custom);
   }
   ]]>
  </fx:Script>
  <mx:TextInput id="mytxt" text="CustomEvent Data" width="140" x="10" y="10"/>
  <mx:Button click="clickHandler(event);" label="Send CustomEvent" x="10" y="40"/>
 </mx:Canvas>
</s:Group>

CustomEvent.as

package customer
{
 import flash.events.Event;
 import flash.events.EventDispatcher;
 public class CustomEvent extends Event
 {
  public static const EVENT_NAME:String="event_name";
  
  public static const dispatcher:EventDispatcher=new EventDispatcher();
  public var data:Object;
  
  public function CustomEvent(type:String, bubbles:Boolean=false, cancelable:Boolean=false, data:Object=null)
  {
   super(type, bubbles, cancelable);
   this.data=data;
  }
  override public function clone():Event{
   return new CustomEvent(type, bubbles, cancelable, data);
  }
 }
}