关于querytask查询的问题； giser

<?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" xmlns:esri="http://www.esri.com/2008/ags" xmlns:renderers="com.esri.ags.renderers.*" >
<fx:Declarations>
  
  <esri:QueryTask url="http://gis/ArcGIS/rest/services/x/MapServer/13" useAMF="false" showBusyCursor="true" id="queryTask">

  </esri:QueryTask>
  <esri:Query   id="query" >
   <esri:outFields>
    <fx:String>NAME</fx:String>
   </esri:outFields>
  </esri:Query>
  <esri:ClassBreaksRenderer>
   <esri:ClassBreakInfo>
    <esri:SimpleFillSymbol id="rfill" alpha="0.5" color="red"/>
   </esri:ClassBreakInfo>
  </esri:ClassBreaksRenderer>
</fx:Declarations>
<fx:Script>
  <![CDATA[
   import com.esri.ags.FeatureSet;
   import com.esri.ags.Graphic;
   import com.esri.ags.SpatialReference;
   import com.esri.ags.geometry.Geometry;
   import com.esri.ags.geometry.MapPoint;
   import com.esri.ags.geometry.Polygon;
   import com.esri.ags.layers.GraphicsLayer;
   import com.esri.ags.symbols.PictureMarkerSymbol;

   import mx.controls.Alert;
   import mx.rpc.AsyncResponder;
   import mx.rpc.events.FaultEvent;

   private var myGraphicLayer:GraphicsLayer=new GraphicsLayer();
   private function doQuery():void
   {
      query.where="NAME like '%"+qText.text+"%'";

      query.returnGeometry=true;

      queryTask.execute(query,new AsyncResponder(OnResult,onFault));

   }


   private function OnResult(featureSet:FeatureSet,token:Object=null):void
   {


    var polygon:Polygon=new Polygon();
    polygon=featureSet.features[0].geometry;
    var graphic:Graphic=new Graphic();
    graphic.geometry=polygon;
    graphic.symbol=rfill;

    myGraphicLayer.clear();

    myGraphicLayer.add(graphic);
    mymap.extent=featureSet.features[0].geometry.extent;
    datagrid.dataProvider=featureSet.attributes;

    mymap.addLayer(myGraphicLayer);

    myGraphicLayer.graphicProvider=featureSet.features;
    //mymap.centerAt(featureSet.features[0].geometry);



   }
    private function onFault(info:Object, token:Object = null):void
   {
    Alert.show(info.toString(), "Query Problem");
   }

  ]]>
</fx:Script>
<esri:Map id="mymap">
  <esri:ArcGISDynamicMapServiceLayer url="http://gis/ArcGIS/rest/services/x/MapServer"/>
</esri:Map>

<s:Panel height="60"
    backgroundColor="0xB2BFC6"
    title="Query a layer (search for a state)">
  <s:layout>
   <s:HorizontalLayout/>
  </s:layout>
  <s:TextInput id="qText"
      width="100%"
      enter="doQuery()"
      text="南京市"/>
  <s:Button click="doQuery()" label="Do Query"/>
</s:Panel>
<mx:DataGrid id="datagrid" bottom="20" width="200" height="150" horizontalCenter="0" />

</s:Application>