Flex4 ButtonBar 双击出现异常，意外吧，看看运行效果就明白了

Flex4 ButtonBar 双击出现异常，意外吧，看看运行效果就明白了

<?xml version="1.0" encoding="utf-8"?>

<!-- dpcontrols\sparkdpcontrols\SparkBBarEvent.mxml -->

<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">

    <s:layout>

        <s:VerticalLayout/>

    </s:layout>

    

    <fx:Script> 

        <![CDATA[ 

            import spark.events.IndexChangeEvent; 

 

            private function changeHandler(event:IndexChangeEvent):void { 

                myTA.text="Selected button index: " + 

                String(event.newIndex) + "\n" + 

                "Selected button label: " + 

                event.target.selectedItem; 

            } 

        ]]> 

    </fx:Script> 

    

    <s:ButtonBar 

        change="changeHandler(event);">

        <mx:ArrayCollection>

            <fx:String>Flash</fx:String> 

            <fx:String>Director</fx:String> 

            <fx:String>Dreamweaver</fx:String> 

            <fx:String>ColdFusion</fx:String> 

        </mx:ArrayCollection>

    </s:ButtonBar> 

 

    <s:TextArea id="myTA" width="250" height="100"/> 

</s:Application>

我只点击第一个Button；

第一次点击：

Selected button index: 0
Selected button label: Flash

第二次点击：

lected button index: -1
Selected button label: undefined