flex中的buffer

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//需要注意的是1、不知道flex ags buffer是否支持自定义投影。因为buffer的spatial都要写wkid的

2、就是直接照着那个例子上的程序敲进去buffer不出来，查了半天知道了问题的所在原来是你要做buffer的图形必须有spatial

，看了一个例子是直接用featureSet.features[i].geometry可是查了帮助也没见features有geometry属性。解决办法

    var featureSet:FeatureSet=new FeatureSet();
                  featureSet.features=[myGraphic];;
                     var featureSet2:FeatureSet=new FeatureSet();

                 for(var i:int=0;i<featureSet.features.length;i++)
                 {
                    var graphic:Graphic=featureSet.features[i];
                   graphic.geometry.spatialReference=new SpatialReference(102100);
                       featureSet2.features= [graphic];
                 }
                  bufferParameters.features=featureSet2.features;

这样就算把空间信息赋值给了features

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" xmlns:esri="http://www.esri.com/2008/ags">
<mx:Canvas width="490" height="401" borderStyle="solid" borderThickness="3" verticalCenter="16" left="10">
    <esri:Map id="myMap" crosshairVisible="true">
        <esri:ArcGISDynamicMapServiceLayer url="http://localhost/ArcGIS/rest/services/ggg/MapServer" />
        <esri:GraphicsLayer id="myGraphicsLayer" />
    </esri:Map>
   </mx:Canvas>
   <mx:DataGrid id="datalist" height="398" verticalCenter="14" borderStyle="solid" borderThickness="3" left="508">
</mx:DataGrid>
<esri:GeometryService id="myGeometryService" url="http://localhost/ArcGIS/rest/services/Geometry/GeometryServer"/>
<esri:SimpleFillSymbol id="sfs" color="0xFF0000" alpha="0.6"/>
    <esri:Draw id="drawToolbar" map="{myMap}" graphicsLayer="{myGraphicsLayer}" drawEnd="drawEndHandler(event)" />
    <mx:ToggleButtonBar verticalCenter="-203" itemClick="itemClickHandler(event)" toggleOnClick="true" left="11">
         <mx:dataProvider>
         <mx:Array>
         <mx:Object icon="{point}" />
         <mx:Object icon="{polyline}" />
       <mx:Object icon="{polygon}" />
       </mx:Array>
        </mx:dataProvider>
    </mx:ToggleButtonBar>
    <esri:IdentifyTask id="identifyTask" identifyComplete="identifyCompleteHandler(event)" url="http://localhost/ArcGIS/rest/services/ggg/MapServer"/>
    <mx:Script>
    <![CDATA[
      import com.esri.ags.geometry.Geometry;
      import com.esri.ags.tasks.FeatureSet;
      import com.esri.ags.tasks.IdentifyResult;
      import com.esri.ags.SpatialReference;
      import com.esri.ags.events.IdentifyEvent;
      import com.esri.ags.tasks.IdentifyParameters;
      import com.esri.ags.events.GeometryServiceEvent;
      import com.esri.ags.tasks.BufferParameters;
      import com.esri.ags.Graphic;
      import mx.events.ItemClickEvent;
      import com.esri.ags.events.DrawEvent;
      import mx.controls.Alert;
       [Bindable]
             [Embed(source="assets/measure-point.png")]
             public var point:Class;
             [Bindable]
             [Embed(source="assets/measure-line.png")]
             public var polyline:Class;
             [Bindable]
             [Embed(source="assets/measure-poly.png")]
             public var polygon:Class;

             private function itemClickHandler(event:ItemClickEvent):void
             {
                 switch(event.index)
                 {
                    case 0:
                     {
                        drawToolbar.activate(Draw.MAPPOINT);
                        break;
                    }
                    case 1:
                    {
                        drawToolbar.activate(Draw.POLYLINE);
                        break;
                    }
                    case 2:
                    {
                        drawToolbar.activate(Draw.POLYGON);
                        break;
                    }
                }
            }



            private function drawEndHandler(event:DrawEvent):void
             {
                 var myGraphic:Graphic=event.graphic;
                //设置buffer参数
                var bufferParameters:BufferParameters = new BufferParameters();


                // bufferParameters.features=[myGraphic];

                  var featureSet:FeatureSet=new FeatureSet();
                  featureSet.features=[myGraphic];;
                     var featureSet2:FeatureSet=new FeatureSet();

                 for(var i:int=0;i<featureSet.features.length;i++)
                 {
                    var graphic:Graphic=featureSet.features[i];
                   graphic.geometry.spatialReference=new SpatialReference(102100);
                       featureSet2.features= [graphic];
                 }
                  bufferParameters.features=featureSet2.features;
                 //buffer距离半径
                 bufferParameters.distances = [2000];
                 //buffer单位
                bufferParameters.unit = BufferParameters.UNIT_METER;
                //buffer空间参照系,102113为WKID是REST API定义好的空间参照系的id
              // bufferParameters.bufferSpatialReference = new SpatialReference(102113);
              //bufferParameters
             // bufferParameters.
               // bufferParameters.outSpatialReference=new SpatialReference(102025);
                bufferParameters.bufferSpatialReference=new SpatialReference(102100);//WGS_1984_Web_Mercator_Auxiliary_Sphere
               // bufferParameters.bufferSpatialReference=new SpatialReference(3349);//WGS_1984_PDC_Mercator
                //添加BUFFER_COMPLETE监听
                  myGeometryService.addEventListener(GeometryServiceEvent.BUFFER_COMPLETE,bufferCompleteHandler);
                //进行buffer分析
                myGeometryService.buffer(bufferParameters);

                Alert.show("123");

                 // myGraphicsLayer.clear();

            }
             private function bufferCompleteHandler(event:GeometryServiceEvent) : void
           {
                Alert.show("456");
                 myGraphicsLayer.clear();
                 //移除BUFFER_COMPLETE监听
                 myGeometryService.removeEventListener(GeometryServiceEvent.BUFFER_COMPLETE,bufferCompleteHandler);
                 //获取buffer结果Graphic
                 for each (var graphic : Graphic in event.graphics )
                 {
                    //设置显示样式
                    graphic.symbol = sfs;
                    //添加到GraphicsLayer进行显示
                    myGraphicsLayer.add( graphic );
                    var identifyParams:IdentifyParameters=new IdentifyParameters();
                    //查询结果需要返回Geometry
                    identifyParams.returnGeometry=true;
                    //查询冗余范围
                    identifyParams.tolerance=1;
                    //宽
                    identifyParams.width = myMap.width;
                    //高
                    identifyParams.height = myMap.height;
                    //设置查询的Geometry
                    identifyParams.geometry=graphic.geometry;
                    //从ComboBox获取选择的图层index设置要查询的图层
                    //查询图层id为2的图层，就是States层
                    identifyParams.layerIds=[7];
                    //查询可见图层
                    identifyParams.layerOption=IdentifyParameters.LAYER_OPTION_VISIBLE;
                    identifyParams.mapExtent=myMap.extent;
                    //进行查询
                    identifyTask.execute(identifyParams);
                }
            }

            private function identifyCompleteHandler(event:IdentifyEvent):void
            {
              //   myNav.activate(Navigation.PAN);
                 var datas:Array=new Array();
                 //myGraphicsLayer.clear();
                 //遍历查询结果把查询到的feature添加到GraphicsLayer进行高亮显示
                 //同时把查询到的元素的名称添加到datas对象数组用来DataGrid显示用
                 for each (var result:IdentifyResult in event.identifyResults)
                {
                    myGraphicsLayer.add(result.feature);
                    //datas.push(result.feature.attributes);
                    datas.push({"value":result.value});
                }
                //设置mx:DataGrid的数据源
                datalist.dataProvider=datas;            }

    ]]>
    </mx:Script>

</mx:Application>