Flex DataGrid插入 删除一行

<?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"> ?<fx:Declarations> ??<!-- 将非可视元素（例如服务、值对象）放在此处 --> ?</fx:Declarations> ?<fx:Script> ??<![CDATA[ ???import flash.profiler.showRedrawRegions; ???import flexunit.utils.ArrayList; ???import mx.collections.ArrayCollection; ???import mx.controls.Alert; ???import mx.controls.List; ???import mx.events.DragEvent; ???import mx.events.FlexEvent; ???[Bindable] ???public var lix:ArrayCollection =new? ArrayCollection([{name:"1",phone:"456",email:"789"},{name:"2",phone:"2",email:"3"}]); ???protected function berfor():void { ????trace(dg.dataProvider.length); ????var item:Object = new Object();? ????var ay:ArrayCollection=dg.dataProvider as ArrayCollection;? ????ay.addItemAt(item,dg.selectedIndex); ????for(var i:int;i<ay.length;i++){ ?????ay.getItemAt(i).name=i+1; ????} ???} ??? ???protected function affter():void{ ????var item:Object = new Object();? ????var ay:ArrayCollection=dg.dataProvider as ArrayCollection;? ????ay.addItemAt(item,dg.selectedIndex+1); ????for(var i:int;i<ay.length;i++){ ?????ay.getItemAt(i).name=i+1; ????} ???} ???protected function dele():void{ ????var ay:ArrayCollection=dg.dataProvider as ArrayCollection; ????var index:int =dg.selectedIndex; ?????dg.dataProvider.removeItemAt(index); ?????index=dg.selectedIndex-1; ?????dg.dataProvider.refresh(); ?????for(var i:int;i<ay.length;i++){ ??????ay.getItemAt(i).name=i+1; ?????} ????} ??? ??]]> ?</fx:Script> ?<s:Panel x="0" y="10" width="100%" height="100%"> ??<s:Button x="128" y="12" label="在之前插入" enabled="{dg.selectedIndex ==-1?false:true}" click="berfor()"/> ??<s:Button x="287" y="12" label="在之后插入" enabled="{dg.selectedIndex ==-1?false:true}" click="affter()"/> ??<s:Button x="445" y="12" label="删除" enabled="{dg.selectedIndex ==-1?false:true}" click="dele()"/> ???<mx:DataGrid id="dg" x="34" y="41" width="581" height="321" dataProvider="{ lix }" ?????? rowCount="5" editable="true"> ????<mx:columns> ?????<mx:DataGridColumn dataField="name" headerText="序号" /> ?????<mx:DataGridColumn dataField="phone" headerText="X坐标"/> ?????<mx:DataGridColumn dataField="email" headerText="Y坐标"/> ????</mx:columns> ???</mx:DataGrid> ?</s:Panel> ? ? ? </s:Application>