ArcGIS.Server.9.3和ArcGIS API for Flex实现Identify的功能图查

发布时间：2020-12-15 04:12:31 所属栏目：百科来源：网络整理

导读：目的： 1.ArcGIS API for Flex 实现Identify的功能，进行图查属性的功能，这样选择图层然后进行点、线、面的查询最好查到的地理元素高亮显示同时在右边的Grid中显示查到的数据。准备工作： 1. 在ArcGIS.Server.9.3发布一个叫usa的Map Service，并且把这个S

目的：
1.ArcGIS API for Flex实现Identify的功能，进行图查属性的功能，这样选择图层然后进行点、线、面的查询最好查到的地理元素高亮显示同时在右边的Grid中显示查到的数据。
准备工作：
1.在ArcGIS.Server.9.3发布一个叫usa的Map Service，并且把这个Service启动起来。
完成后的效果图：

开始：
1.启动Flex Builder3新建工程以及引入ArcGIS API for Flex library的开发包。
2.新建IdentifyTest.mxml页面，然后在页面上添加esri:Map控件设置esri:ArcGISDynamicMapServiceLayer等，这里还需要高亮显示被查询到的元素所以还需要esri:GraphicsLayer，具体代码如下：

 
  
 
 
1
<mx:Canvas?width="490"?height="311"?borderStyle="solid"?borderThickness="3"?borderColor="#425DE2"?verticalCenter="-20"?x="11">
2
????<esri:Map?id="myMap">
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????????<mx:Panel?x="209"?y="-10"?width="250"?height="200"?layout="absolute">
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????????</mx:Panel>
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????????<esri:ArcGISDynamicMapServiceLayer?id="myMapServiceLayer"?url="http://jh-53a435fbc0e8/ArcGIS/rest/services/USA/MapServer"?complete="mapHandler(event)"/>
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????????<esri:GraphicsLayer?id="myGraphicsLayer"?symbolFunction="{mySymbolFunction}"/>
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????</esri:Map>
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????</mx:Canvas> 
 

3.上面的代码中给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上方的mx:ComboBox上，代码如下：

// 获取地图图层名称和index到ComboBox上
?2

????????????private? function ?mapHandler(event:Event): void
?3

???????????? {
?4

????????????????//获取图层信息数组
?5

????????????????var?layerInfos:Array;
?6

????????????????layerInfos=myMapServiceLayer.layerInfos;
?7

????????????????var?layers:Array?=?new?Array();
?8

????????????????//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
?9

????????????????for(var?i:int=0;i<layerInfos.length;i++)
10

????????????????{
11

????????????????????layers.push({label:layerInfos[i].name?,data:i});?
12

????????????????}
13

????????????????//给ComboBox设定数据源
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????????????????layerList.dataProvider=layers;
15

????????????}

mx:ComboBox显示代码：

< mx:ComboBox? id ="layerList" ?verticalCenter ="-195" ?x ="139" ></ mx:ComboBox >

4.上面的GraphicsLayer也添加了一个symbolFunction的功能，这个功能是当有元素添加到 GraphicsLayer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，代码如下：

private? function ?mySymbolFunction(graphic:Graphic):Symbol
?2

???????????? {
?3

????????????????var?result:Symbol;
?4

????????????????//根据元素的类型进行显示样式的设定
?5

????????????????switch(graphic.geometry.type)
?6

????????????????{
?7

????????????????????case?Geometry.GEOMETRY_POINT:
?8

????????????????????{
?9

????????????????????????result=sms;
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????????????????????????break;
11

????????????????????}
12

????????????????????case?Geometry.GEOMETRY_POLYLINE:
13

????????????????????{
14

????????????????????????result=sls;
15

????????????????????????break;
16

????????????????????}
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????????????????????case?Geometry.GEOMETRY_POLYGON:
18

????????????????????{
19

????????????????????????result=sfs;
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????????????????????????break;
21

????????????????????}
22

????????????????}
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????????????????return?result;
24

????????????}

5.上面代码中的sms、sls、sfs是定义好的Symbol的id,具体定义如下：

< esri:SimpleLineSymbol? id ="sls" ?style ="solid" ?color ="0x00FF00" ?width ="2" ?alpha ="1" />
2

???? < esri:SimpleMarkerSymbol? id ="sms" ?style ="diamond" ?color ="0x00FF00" ?size ="15" />
3

???? < esri:SimpleFillSymbol? id ="sfs" />

6.要画图肯定还需要esri:Draw这个控件了，上一篇有比较详细的讲了这里就不说了，代码如下：

< esri:Draw? id ="drawToolbar" ?map ="{myMap}" ?graphicsLayer ="{myGraphicsLayer}" ?drawEnd ="drawEndHandler(event)" ? />

7.接着添加mx:ToggleButtonBar了，添加3个子按钮分别是点、线、面的操作，具体代码如下：

< mx:ToggleButtonBar? verticalCenter ="-195" ??itemClick ="itemClickHandler(event)" ?x ="11" ?toggleOnClick ="true" >
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???????? < mx:dataProvider >
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???????? < mx:Array >
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???????? < mx:Object? icon ="{point}" ? />
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???????? < mx:Object? icon ="{polyline}" ? />
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???????? < mx:Object? icon ="{polygon}" ? />
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???????? </ mx:Array >
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???????? </ mx:dataProvider >
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???? </ mx:ToggleButtonBar >

8. ToggleButtonBar的itemClickHandler事件代码：

private? function ?itemClickHandler(event:ItemClickEvent): void
?2

???????????? {
?3

????????????????switch(event.index)
?4

????????????????{
?5

????????????????????case?0:
?6

????????????????????{
?7

????????????????????????drawToolbar.activate(Draw.MAPPOINT);
?8

????????????????????????break;
?9

????????????????????}
10

????????????????????case?1:
11

????????????????????{
12

????????????????????????drawToolbar.activate(Draw.POLYLINE);
13

????????????????????????break;
14

????????????????????}
15

????????????????????case?2:
16

????????????????????{
17

????????????????????????drawToolbar.activate(Draw.POLYGON);
18

????????????????????????break;
19

????????????????????}
20

????????????????}
21

????????????}

9.这样就实现了能在GraphicsLayer上画点、线、面的功能，接下来就是今天主要的代码就是在上面添加 esri:Draw的时候给它添加了一个drawEnd="drawEndHandler(event)"，这个就是当绘图完成后执行drawEndHandler(event)这个方法了，主要功能就是在这个方法里实现Identify的功能的，要实现Identify的功能还需要添加一个esri:IdentifyTask控件，这个就是实现 Identify的功能的控件，添加控件代码如下：

< esri:IdentifyTask? id ="identifyTask" ?identifyComplete ="identifyCompleteHandler(event)" ?url ="http://jh-53a435fbc0e8/ArcGIS/rest/services/USA/MapServer" />

mx:DataGrid的显示代码：

< mx:DataGrid? id ="datalist" ?height ="311" ?borderStyle ="solid" ?borderThickness ="3" ?verticalCenter ="-20" ?borderColor ="#1B67D9" ?left ="509" >

drawEndHandler(event)的代码如下：

private? function ?drawEndHandler(event:DrawEvent): void
?2

???????????? {
?3

????????????????//获取绘图结果Geometry
?4

????????????????var?geometry:Geometry=event.geometry;
?5

????????????????var?identifyParams:IdentifyParameters=new?IdentifyParameters();
?6

????????????????//查询结果需要返回Geometry
?7

????????????????identifyParams.returnGeometry=true;
?8

????????????????//查询冗余范围
?9

????????????????identifyParams.tolerance=3;
10

????????????????//宽
11

????????????????identifyParams.width?=?myMap.width;
12

????????????????//高
13

????????????????identifyParams.height?=?myMap.height;
14

????????????????//设置查询的Geometry
15

????????????????identifyParams.geometry=geometry;
16

????????????????//从ComboBox获取选择的图层index设置要查询的图层
17

????????????????var?layers:Array=new?Array();
18

????????????????layers.push(layerList.value);
19

????????????????identifyParams.layerIds=layers;
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????????????????//查询可见图层
21

????????????????identifyParams.layerOption=IdentifyParameters.LAYER_OPTION_VISIBLE;
22

????????????????
23

????????????????identifyParams.mapExtent=myMap.extent;
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????????????????//进行查询
25

????????????????identifyTask.execute(identifyParams);
26

????????????}
27

????????????
28

???????????? // 查询完成后执行的事件
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????????????private? function ?identifyCompleteHandler(event:IdentifyEvent): void
30

???????????? {
31

????????????????var?datas:Array=new?Array();
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????????????????//myGraphicsLayer.clear();
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????????????????//遍历查询结果把查询到的feature添加到GraphicsLayer进行高亮显示
34

????????????????//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
35

????????????????for?each?(var?result:IdentifyResult?in?event.identifyResults)
36

????????????????{
37

????????????????????myGraphicsLayer.add(result.feature);
38

????????????????????//datas.push(result.feature.attributes);????
39

????????????????????datas.push({"value":result.value});
40

????????????????}
41

????????????????//设置mx:DataGrid的数据源
42

????????????????datalist.dataProvider=datas;
43

????????????}

10.这样就完成了所有的代码可以运行测试效果了。

（编辑：李大同）

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