ArcGIS Api for js之缩放至图层

///----------------------------------------------------------
//前置条件：地图全局变量的名称为map
//功能：对行政区划地图中的县城图层
//      查询当前操作的县城
//      通过查询，使当前地图视图为该县城的范围，达到缩放至图层的效果
require(["dojo/parser",
    "dijit/registry",
    'dojo/on',
    "dojo/dom",
    "esri/map",
    "esri/layers/ArcGISDynamicMapServiceLayer",
    "esri/tasks/FindTask",
     "esri/tasks/FindParameters",
    "esri/symbols/SimpleLineSymbol",
    "esri/symbols/SimpleFillSymbol",
    "esri/graphic",
    "dojo/domReady!"],
   function (parser, registry, on, dom, Map, ArcGISDynamicMapServiceLayer, FindTask, FindParameters, SimpleLineSymbol, SimpleFillSymbol) {
       //parser.parse();
       var findTask = new FindTask("http://localhost:6080/arcgis/rest/services/henan/MapServer");
       var FindParameters = new FindParameters();
       var xzFieldName = ["xxx"];//字段名称
       var xzFieldValue = "xxxx";//县名       
       on(dom.byId("BtnSetExtent"), "click", FindByField);

       //对字段进行查询
       function FindByField() {
           FindParameters.returnGeometry = true;
           FindParameters.layerIds = [0];
           FindParameters.searchFields = xzFieldName;
           FindParameters.searchText = xzFieldValue;
           findTask.execute(FindParameters, ShowFindResult);
           //alert("3");
       }
       //属性查询结果处理
       function ShowFindResult(queryResult) {
           if (queryResult.length > 0) {
               var feature = queryResult[0].feature;//[0].feature;

               //创建线符号
               var lineSymbol = new SimpleLineSymbol(SimpleLineSymbol.STYLE_SOLID, new dojo.Color([54, 141, 58]), 2);
               //创建面符号
               var fill = new SimpleFillSymbol(SimpleFillSymbol.STYLE_NULL, lineSymbol);
               //赋予相应的符号
               feature.setSymbol(fill);
               pMap.graphics.clear();
               pMap.graphics.add(feature);
               var sGeometry = feature.geometry;
               var ftGeoExt = sGeometry.getExtent();
               
               pMap.setExtent(ftGeoExt);
               
           }
       }
   });