IdentifyTask - 走看看

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IdentifyTask

1.功能：

选择图层然后按照用户所画的点，线，面查询属性，并且对查到的地理元素进行高亮显示同时在右边的Grid中显示查到的数据。

2.效果图：

3.步骤

新建identifytest.mxml页面，然后在页面上添加map控件以及需要高亮显示被查询到的元素的GraphicsLayer：

View Code

    <esri:Map id="myMap">

        <esri:ArcGISDynamicMapServiceLayer id="myMapServiceLayer" url="http://192.168.47.29:8399/arcgis/rest/services/China/MapServer" complete="mapHandler(event)">
        </esri:ArcGISDynamicMapServiceLayer>
        <esri:GraphicsLayer id="myGraphicsLayer" symbolFunction="{mySymbolFunction}">
        </esri:GraphicsLayer>
        <esri:extent>
            <esri:Extent  id = "esriMapExtent" xmin="73.4" ymin="13.33" xmax="135.2" ymax="63.4"/>
        </esri:extent>
    </esri:Map>

代码中给ArcGISDynamicMapServiceLayer添加了一个complete事件用来当地图载入完成后获取地图的图层名称显示在地图下方的ComboBox上：

<mx:ComboBox id="layerList" verticalCenter="500" x="139">
</mx:ComboBox>

View Code

//获取地图图层名称和index到combobox上
        private function mapHandler(event:Event):void{
            //获取图层信息数组
            var layerInfos:Array;
            layerInfos=myMapServiceLayer.layerInfos;
            var layers:Array=new Array();
            //遍历图层信息数组然后把图层的名称和index值添加到新的数组中
            for(var i:int = 0;i<layerInfos.length;i++){
                layers.push({label:layerInfos[i].name,data:i});

            }
            //给Combox设定数据源
            layerList.dataProvider=layers;

        }

同时，在GraphicsLayer中也添加了一个symbolFunction的功能，这个功能是当有元素添加到GraphicLayer时进行元素显示样式的设置，这样分别对点、线、面进行样式设定：

<esri:SimpleMarkerSymbol id="sms" style="diamond" color="0x00ff00" size="15"/>
<esri:SimpleLineSymbol id="sls" style="solid" color="0x00ff00" width="2" alpha="1"/>
<esri:SimpleFillSymbol id="sfs"/>

View Code

//symbolFunction的功能是当有元素添加到graphiclayer时进行元素显示样式的设置，这样分别对点、线、面进行设定
        private function mySymbolFunction(graphic:Graphic):Symbol{
            var result:Symbol;
            //根据元素的类型进行显示样式的设定
            switch(graphic.geometry.type){
                case Geometry.MAPPOINT:{result=sms;break;}
                case Geometry.POLYLINE:{result=sls;break;}
                case Geometry.POLYGON:{result=sfs;break;}
            }
            return result;
        }

要有画图和一些常规按钮，实现放大，缩小等常规功能，以及实现能在GraphicsLayer上画点、线、面的功能，代码如下：

View Code

<esri:Navigation id="navToolbar" map="{myMap}"/>
    <esri:Draw id="drawToolbar" map="{myMap}" graphicsLayer="{myGraphicsLayer}" drawEnd="drawEndHandler(event)"/>
    <mx:HBox horizontalAlign="center" width="100%">
        <mx:ControlBar horizontalGap="0" paddingBottom="0" paddingTop="0">
            <mx:Button label="放大"   click="navToolbar.activate(Navigation.ZOOM_IN)"  />
            <mx:Button label="缩小"   click="navToolbar.activate(Navigation.ZOOM_OUT)"  />
            <mx:Button label="漫游"   click="navToolbar.activate(Navigation.PAN)"  />
            <mx:Button label="上级窗口"   click="navToolbar.zoomToPrevExtent()" enabled="{!navToolbar.isFirstExtent}"/>
            <mx:Button label="下级窗口"   click="navToolbar.zoomToNextExtent()"    enabled="{!navToolbar.isLastExtent}"/>
            <mx:Button label="复位" click="navToolbar.zoomToFullExtent()"/>

            <mx:Button label="点"   click="drawToolbar.activate(Draw.MAPPOINT)"  />
            <mx:Button label="线"   click="drawToolbar.activate(Draw.POLYLINE)"  />
            <mx:Button label="流线"   click="drawToolbar.activate(Draw.FREEHAND_POLYLINE)"  />
            <mx:Button label="矩形"   click="drawToolbar.activate(Draw.EXTENT)"  />
            <mx:Button label="多边形"   click="drawToolbar.activate(Draw.POLYGON)"   />
            <mx:Button label="流多边形"      click="drawToolbar.activate(Draw.FREEHAND_POLYGON) "/>
            <mx:Button label="结束绘制"      click="drawToolbar.deactivate() "/>
        </mx:ControlBar>
    </mx:HBox>

最后，就是在esri:Draw组件中添加一个drawEnd属性，它的功能是当绘图完成后执行drawEndHandler(event)方法，我们在这个方法里实现Identify的功能。代码如下：

<esri:IdentifyTask id="identifyTask" identifyComplete="identifyCompleteHandler(event)" url="http://192.168.47.29:8399/arcgis/rest/services/China/MapServer%22/>

View Code

private function drawEndHandler(event:DrawEvent):void{
            //获取绘图结果Geometry
            var geometry:Geometry=event.graphic.geometry;
            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=3;
            identifyParams.width=myMap.width;
            identifyParams.height=myMap.height;
            //设置查询的geometry
            identifyParams.geometry=geometry;
            //从ComboBox获取选择的图层index设置要查询的图层
            var layers:Array=new Array();
            layers.push(layerList.value);
            identifyParams.layerIds=layers;
            //查询可见图层
            identifyParams.layerOption=IdentifyParameters.LAYER_OPTION_VISIBLE;
            identifyParams.mapExtent=myMap.extent;
            //进行查询
            identifyTask.execute(identifyParams);

        }
//查询完成后执行的事件
        private function identifyCompleteHandler(event:IdentifyEvent):void{
            var datas:Array=new Array();
            //myGraphicsLayer.clear();
            //遍历查询结果把查询到的feature添加到GraphicLayer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})
            }
            datalist.dataProvider=datas;
        }

ok!做完以上事情后就大功告成了！

现附上全部代码如下：

View Code

<?xml version="1.0" encoding="utf-8"?>

<mx:Application

    xmlns:mx="http://www.adobe.com/2006/mxml"

    xmlns:esri="http://www.esri.com/2008/ags"

    pageTitle="Query Task"

    >
<mx:Script>
    <![CDATA[
        import com.esri.ags.Graphic;
        import com.esri.ags.events.DrawEvent;
        import com.esri.ags.events.IdentifyEvent;
        import com.esri.ags.geometry.Geometry;
        import com.esri.ags.symbol.Symbol;
        import com.esri.ags.tasks.IdentifyParameters;
        import com.esri.ags.tasks.IdentifyResult;
        //获取地图图层名称和index到combobox上
        private function mapHandler(event:Event):void{
            //获取图层信息数组
            var layerInfos:Array;
            layerInfos=myMapServiceLayer.layerInfos;
            var layers:Array=new Array();
            //遍历图层信息数组然后把图层的名称和index值添加到新的数组中
            for(var i:int = 0;i<layerInfos.length;i++){
                layers.push({label:layerInfos[i].name,data:i});

            }
            //给Combox设定数据源
            layerList.dataProvider=layers;

        }
        //symbolFunction的功能是当有元素添加到graphiclayer时进行元素显示样式的设置，这样分别对点、线、面进行设定
        private function mySymbolFunction(graphic:Graphic):Symbol{
            var result:Symbol;
            //根据元素的类型进行显示样式的设定
            switch(graphic.geometry.type){
                case Geometry.MAPPOINT:{result=sms;break;}
                case Geometry.POLYLINE:{result=sls;break;}
                case Geometry.POLYGON:{result=sfs;break;}
            }
            return result;
        }

        private function drawEndHandler(event:DrawEvent):void{
            //获取绘图结果Geometry
            var geometry:Geometry=event.graphic.geometry;
            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=3;
            identifyParams.width=myMap.width;
            identifyParams.height=myMap.height;
            //设置查询的geometry
            identifyParams.geometry=geometry;
            //从ComboBox获取选择的图层index设置要查询的图层
            var layers:Array=new Array();
            layers.push(layerList.value);
            identifyParams.layerIds=layers;
            //查询可见图层
            identifyParams.layerOption=IdentifyParameters.LAYER_OPTION_VISIBLE;
            identifyParams.mapExtent=myMap.extent;
            //进行查询
            identifyTask.execute(identifyParams);

        }

        //查询完成后执行的事件
        private function identifyCompleteHandler(event:IdentifyEvent):void{
            var datas:Array=new Array();
            //myGraphicsLayer.clear();
            //遍历查询结果把查询到的feature添加到GraphicLayer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})
            }
            datalist.dataProvider=datas;
        }
    ]]>
</mx:Script>
    <esri:SimpleMarkerSymbol id="sms" style="diamond" color="0x00ff00" size="15"/>
    <esri:SimpleLineSymbol id="sls" style="solid" color="0x00ff00" width="2" alpha="1"/>
    <esri:SimpleFillSymbol id="sfs"/>
    <esri:Navigation id="navToolbar" map="{myMap}"/>
    <esri:Draw id="drawToolbar" map="{myMap}" graphicsLayer="{myGraphicsLayer}" drawEnd="drawEndHandler(event)"/>
    <esri:IdentifyTask id="identifyTask" identifyComplete="identifyCompleteHandler(event)" url="http://192.168.47.29:8399/arcgis/rest/services/China/MapServer"/>

    
    <esri:Map id="myMap">

        <esri:ArcGISDynamicMapServiceLayer id="myMapServiceLayer" url="http://192.168.47.29:8399/arcgis/rest/services/China/MapServer" complete="mapHandler(event)">
        </esri:ArcGISDynamicMapServiceLayer>
        <esri:GraphicsLayer id="myGraphicsLayer" symbolFunction="{mySymbolFunction}">
        </esri:GraphicsLayer>
        <esri:extent>
            <esri:Extent  id = "esriMapExtent" xmin="73.4" ymin="13.33" xmax="135.2" ymax="63.4"/>
        </esri:extent>
    </esri:Map>

    <mx:HBox horizontalAlign="center" width="100%">
        <mx:ControlBar horizontalGap="0" paddingBottom="0" paddingTop="0">
            <mx:Button label="放大"   click="navToolbar.activate(Navigation.ZOOM_IN)"  />
            <mx:Button label="缩小"   click="navToolbar.activate(Navigation.ZOOM_OUT)"  />
            <mx:Button label="漫游"   click="navToolbar.activate(Navigation.PAN)"  />
            <mx:Button label="上级窗口"   click="navToolbar.zoomToPrevExtent()" enabled="{!navToolbar.isFirstExtent}"/>
            <mx:Button label="下级窗口"   click="navToolbar.zoomToNextExtent()"    enabled="{!navToolbar.isLastExtent}"/>
            <mx:Button label="复位" click="navToolbar.zoomToFullExtent()"/>

            <mx:Button label="点"   click="drawToolbar.activate(Draw.MAPPOINT)"  />
            <mx:Button label="线"   click="drawToolbar.activate(Draw.POLYLINE)"  />
            <mx:Button label="流线"   click="drawToolbar.activate(Draw.FREEHAND_POLYLINE)"  />
            <mx:Button label="矩形"   click="drawToolbar.activate(Draw.EXTENT)"  />
            <mx:Button label="多边形"   click="drawToolbar.activate(Draw.POLYGON)"   />
            <mx:Button label="流多边形"      click="drawToolbar.activate(Draw.FREEHAND_POLYGON) "/>
            <mx:Button label="结束绘制"      click="drawToolbar.deactivate() "/>
        </mx:ControlBar>
    </mx:HBox>


<mx:ComboBox id="layerList" verticalCenter="500" x="139">
</mx:ComboBox>
<mx:DataGrid id="datalist" height="100" borderColor="#1b67d9" borderStyle="solid" borderThickness="3" verticalCenter="-20" left="509"/>


</mx:Application>

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原文地址：https://www.cnblogs.com/pandy/p/1988919.html