Spark List組件滾動條加事件使datalist數據發生變化

<?xml version="1.0" encoding="utf-8"?>
<!--?http://blog.flexexamples.com/2009/05/31/detecting-when-the-vertical-scroll-bar-is-scrolled-on-a-spark-list-control-in-flex-4/?-->
<s:Application name="Spark_List_scroller_verticalScrollBar_change_test"
??????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:Script>
??<![CDATA[
???import spark.components.VScrollBar;
???
???private function init():void {
????list.scroller.verticalScrollBar.addEventListener(Event.CHANGE, list_verticalScrollBar_change);
???}
???
???private function list_verticalScrollBar_change(evt:Event):void {
????var vsb:VScrollBar = evt.currentTarget as VScrollBar;
????var obj:Object = {};
????obj.type = evt.type;
????obj.val = vsb.value;
????obj.max = vsb.maximum;
????arrColl.addItem(obj);
????callLater(dgScroll);
???}
???
???private function dgScroll():void {
????dataGrid.verticalScrollPosition =?dataGrid.maxVerticalScrollPosition;
???}
??]]>
?</fx:Script>
?
?<fx:Declarations>
??<mx:ArrayCollection id="arrColl" />
?</fx:Declarations>
?
?<s:HGroup horizontalCenter="0" verticalCenter="0">
??<s:List id="list"
????creationComplete="init();">
???<s:layout>
????<s:VerticalLayout gap="0"
??????????horizontalAlign="contentJustify"
??????????requestedRowCount="4" />
???</s:layout>
???<s:dataProvider>
????<s:ArrayList>
?????<fx:String>The</fx:String>
?????<fx:String>Quick</fx:String>
?????<fx:String>Brown</fx:String>
?????<fx:String>Fox</fx:String>
?????<fx:String>Jumps</fx:String>
?????<fx:String>Over</fx:String>
?????<fx:String>The</fx:String>
?????<fx:String>Lazy</fx:String>
?????<fx:String>Dog</fx:String>
????</s:ArrayList>
???</s:dataProvider>
??</s:List>
??<mx:DataGrid id="dataGrid"
??????dataProvider="{arrColl}"
??????width="200"
??????verticalScrollPolicy="on">
???<mx:columns>
????<mx:DataGridColumn dataField="type" />
????<mx:DataGridColumn dataField="val" />
????<mx:DataGridColumn dataField="max" />
???</mx:columns>
??</mx:DataGrid>
?</s:HGroup>
?
</s:Application>