Flex 优化Renderer(不使用HGroup)

package {import mx.controls.dataGridClasses.DataGridListData;import mx.controls.listClasses.BaseListData;import mx.controls.listClasses.IDropInListItemRenderer;import mx.controls.listClasses.IListItemRenderer;import mx.core.UIComponent;import mx.events.FlexEvent;public class BaseRenderer extends UIComponent implements Tabable, IListItemRenderer, IDropInListItemRenderer{private var _dataIndex:int=-1;private var _listData:DataGridListData;private var _data:Object;public function BaseRenderer(){super();}public function get dataIndex():int{return _dataIndex;}public function set dataIndex(value:int):void{_dataIndex=value;}[Bindable("dataChange")]public function get data():Object{return _data;}public function get listData():BaseListData{return _listData;}public function set listData(value:BaseListData):void{_listData=DataGridListData(value);}public function set data(value:Object):void{_data=value;this.dataIndex=(listData.owner).dataProvider.getItemIndex(data);this.invalidateProperties();dispatchEvent(new FlexEvent("dataChange"));}override protected function createChildren():void{super.createChildren();}override protected function commitProperties():void{super.commitProperties();updateRenderer();}override protected function measure():void{super.measure();//this.measuredHeight=22;}protected function updateRenderer():void{}public function get text():Object{return "";}public function getFocusable():UIComponent{return null;}/** * initialize a new instance */public function newInstance():*{return new BaseRenderer();}}}