FLEX 事件机制-自定义事件介绍

最近在做地图JS和FLEX的封装工作，flex封装需要用到自定义事件这方面知识，在这里就简单介绍一下FLEX自定义事件。

自定义事件必须注意几点：

（1）自定义事件通过继承Event类来实现。

（2）自定义事件不可以自己触发，只能有系统事件派发。

首先我们新建一个ActionScript 类，这个类继承flash.events.Event。


代码如下:

package
{
import flash.events.Event;

public class MyEvent extends Event
{
public static const myEvent:String="myEvent";

public var data:*;

public function MyEvent(type:String,bubbles:Boolean=false,cancellabel:Boolean=false,data:* = null)
{
super(type,false,false);
this.data = data;
}

override public function clone():Event{
return new MyEvent(myEvent,false,false,data);
}

override public function toString():String{

return formatToString("MyEvent");
}
}
}

创建一个组件来监听事件，实现数据的接受。

component.mxml


代码如下:

<?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="100%" height="100%" initialize="init()">
<s:layout>
<s:BasicLayout/>
</s:layout>

<fx:Script>
<![CDATA[
import mx.controls.Alert;
import mx.events.FlexEvent;
public var ff:FlexMyEvent;

public function init():void{

ff = this.parentDocument as FlexMyEvent;
ff.addEventListener(MyEvent.myEvent,myEventHandler);//监听事件

}
public function myEventHandler(eve:Object):void{

inpu.text = eve.data;
Alert.show("事件触发，"+eve.data);
}

]]>
</fx:Script>

<fx:Declarations>
<!-- 将非可视元素（例如服务、值对象）放在此处 -->
</fx:Declarations>

<s:Panel width="100%" height="100%" backgroundColor="#E7D4DD">

<s:TextInput id="inpu">

</s:TextInput>

</s:Panel>

</s:Group>

主程序

FlexMyEvent.mxml


代码如下:

<?xml version="1.0" encoding="utf-8"?>
<s:Application 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:comp = "*"
width="100%" height="100%">

<fx:Script>
<![CDATA[

import flash.external.ExternalInterface;
import flash.system.Security;

import mx.controls.Alert;
import mx.events.FlexEvent;
public var callBackInfo:String = "";
public function doSend():void{

callBackInfo = input.text;
var myEve:MyEvent = new MyEvent(MyEvent.myEvent,false,false,callBackInfo);//派发事件 myEve.data is Object;
this.dispatchEvent(myEve);

}

]]>
</fx:Script>

<fx:Declarations>
<!-- 将非可视元素（例如服务、值对象）放在此处 -->
</fx:Declarations>

<mx:HBox width="100%" height="100%" horizontalAlign="center" verticalAlign="middle">

<s:Panel width="100%" height="100%">
<mx:HBox paddingLeft="5" width="100%" height="100%">
<s:TextInput id="input" text="Send Hello">

</s:TextInput>
<s:Button label="Send" click="doSend()">

</s:Button>
</mx:HBox>
</s:Panel>

<comp:Component>

</comp:Component>
</mx:HBox>

</s:Application>