开始的时候不知道该怎么写自定义事件，怎感觉很麻烦，其实理解就不麻烦了。
（一）首先你要定义一个事件，让这个事件继承event；放在events包下（建一个events包）
package events{
?? ?import flash.events.Event;
?? ?public class MyEvent extends Event{
?? ??? ?public var str:String;? //要传的值，也可以是对象
//构造函数改写
?? ??? ?public function MyEvent(type:String,str:String){
?? ??? ??? ?super(type);
?? ??? ??? ?this.str= str;
?? ??? ?}
?? ?}
}
（二）你可以自定义组件使用这个事件，比如我定义一个两个按钮的组件
<?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">
?? ?<fx:Metadata>
?? ??? ?[Event(name="aaa",type="events.MyEvent")]? //定义元数据也是声明事件
?? ??? ?[Event(name="bbb",type="events.MyEvent")] //定义元数据也是声明事件
?? ?</fx:Metadata>
?? ?<fx:Script>
?? ??? ?<![CDATA[
?? ??? ??? ?import events.MyEvent;
?? ??? ??? ?protected function ok_handelEvent(event:MouseEvent):void{
?? ??? ??? ??? ?var okEvent:MyEvent = new MyEvent("aaa","要传的值");
?? ??? ??? ??? ?this.dispatchEvent(okEvent);
?? ??? ??? ?}
?? ??? ??? ?
?? ??? ??? ?protected function cancel_handelEvent(event:MouseEvent):void{
?? ??? ??? ??? ?var cancelEvent:MyEvent = new MyEvent("bbb","取消的值");
?? ??? ??? ??? ?this.dispatchEvent(cancelEvent);
?? ??? ??? ?}
?? ??? ?]]>
?? ?</fx:Script>
?? ?<s:Button label="确定" click="ok_handelEvent(event)"/>
?? ?<s:Button x="132" y="0" label="取消" click="cancel_handelEvent(event)"/>
</s:Group>
（三）使用事件
<?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" minWidth="955" minHeight="600" xmlns:componnet="componnet.*">
?? ?<fx:Script>
?? ??? ?<![CDATA[
?? ??? ??? ?import events.MyEvent;
?? ??? ??? ?import mx.controls.Alert;
?? ??? ??? ?protected function mybutton1_aaaHandler(event:MyEvent):void{
?? ??? ??? ??? ?Alert.show(event.str);
?? ??? ??? ?}
?? ??? ??? ?protected function mybutton1_bbbHandler(event:MyEvent):void{
?? ??? ??? ??? ?Alert.show(event.str);
?? ??? ??? ?}
?? ??? ?]]>
?? ?</fx:Script>
?? ?<componnet:MyButton x="360" y="125" aaa="mybutton1_aaaHandler(event)" ?? ??? ??? ??? ??? ??? ?bbb="mybutton1_bbbHandler(event)"/> </s:Application>
