<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/10/08/setting-a-label-function-on-a-linkbar-control-in-flex/ -->
<mx:Application name="LinkBar_labelFunction_test"
        xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white" viewSourceURL="srcview/index.html">

    <mx:Script>
        <![CDATA[
            import mx.core.Container;

            private function linkBar_labelFunc(item:Container):String {
                return item[linkBar.labelField].toUpperCase();
            }
        ]]>
    </mx:Script>

    <mx:Array id="arr1">
        <mx:Object label="One fish" />
        <mx:Object label="Two fish" />
    </mx:Array>

    <mx:Array id="arr2">
        <mx:Object label="Red fish" />
        <mx:Object label="Blue fish" />
    </mx:Array>

    <mx:LinkBar id="linkBar"
            dataProvider="{viewStack}"
            labelFunction="linkBar_labelFunc" />

    <mx:ViewStack id="viewStack" width="200">
        <mx:VBox label="VBox One">
            <mx:DataGrid id="dataGrid1"
                    dataProvider="{arr1}"
                    draggableColumns="false"
                    width="100%"
                    height="100%" />
        </mx:VBox>
        <mx:VBox label="VBox Two">
            <mx:DataGrid id="dataGrid2"
                    dataProvider="{arr2}"
                    draggableColumns="false"
                    width="100%"
                    height="100%" />
        </mx:VBox>
    </mx:ViewStack>

</mx:Application>