<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/01/09/determining-which-button-was-pressed-in-a-flex-buttonbar-component/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="top"
        backgroundColor="white" viewSourceURL="srcview/index.html">

    <mx:Script>
        <![CDATA[
            import mx.controls.Alert;
            import mx.controls.buttonBarClasses.ButtonBarButton;
            import mx.events.ItemClickEvent;
            import mx.utils.ObjectUtil;

            private function buttonBar_itemClick(evt:ItemClickEvent):void {
                var message:String = ObjectUtil.toString(evt.item);
                var title:String = "[" + evt.index + "] " + evt.label;
                Alert.show("item: " + message, title);
            }
        ]]>
    </mx:Script>
    
    <mx:Array id="arr">
        <mx:Object label="One" data="15" />
        <mx:Object label="Two" data="12" custom="seven" />
        <mx:Object label="Three" data="9" />
        <mx:Object label="Four" custom="eleven" />
        <mx:Object label="Five" name="Peter" />
    </mx:Array>
    
    <mx:ButtonBar id="buttonBar"
            dataProvider="{arr}"
            itemClick="buttonBar_itemClick(event);" />

</mx:Application>