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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QueryTest.mxml页面,这里显示的地图采用Esri提供的在线的NPS_Physical_World_2D的地图比较的漂亮,但是Tiled图没有图层以及字段等数据没有办法进行查询定位,所以在Tiled图的基础上在叠加一个DynamicMap图层就是上面发布的usa的数据,我们对usa的数据进行查询然后结果显示在NPS_Physical_World_2D的地图上面。由于是2个Layer的叠加就需要esri:ArcGISTiledMapServiceLayer和ArcGISDynamicMapServiceLayer,具体的显示代码如下: |
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--> 1<esri:Extent id="myExtent" xmin="-127.968857954995" ymin="25.5778580720472" xmax="-65.0742781827045" ymax="51.2983251993735" /> |
 2    <mx:Canvas width="434" height="370" borderStyle="solid" borderThickness="3" borderColor="#D6D7D8" horizontalCenter="-140" verticalCenter="34"> |
 3    <esri:Map id="myMap" extent="{myExtent}"> |
 4        <esri:ArcGISTiledMapServiceLayer url="http://server.arcgisonline.com/ArcGIS/rest/services/NPS_Physical_World_2D/MapServer" /> |
 5        <esri:ArcGISDynamicMapServiceLayer id="myMapServiceLayer"  url="http://jh-53a435fbc0e8/ArcGIS/rest/services/USA/MapServer" creationComplete="loadMapLayer(event)"> |
 6            <esri:visibleLayers> |
 7            <mx:ArrayCollection> |
 8            </mx:ArrayCollection> |
 9            </esri:visibleLayers> |
10        </esri:ArcGISDynamicMapServiceLayer> |
11        <esri:GraphicsLayer id="myGraphicsLayer"  symbolFunction="{mySymbolFunction}" /> |
12    </esri:Map> |
13    </mx:Canvas> |
3.上面的代码中为Map控件设置了以为USA范围的Extent,为ArcGISDynamicMapServiceLayer设置了creationComplete事件就是用来执行loadMapLayer(event)把地图图层名称以及index添加到ComboBox来选择用。 |
loadMapLayer(event)方法代码如下: |
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--> 1//获取地图图层名称和index到ComboBox上 |
 2            private function loadMapLayer(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.name ,data:i});  |
12                } |
13                //给ComboBox设定数据源 |
14                layerList.dataProvider=layers; |
15            } |
ComboBox的显示代码: |
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-->1<mx:ComboBox id="layerList" x="10" y="10" width="117"></mx:ComboBox> |
4.上面还为ArcGISDynamicMapServiceLayer设置了可视图层<esri:visibleLayers><mx:ArrayCollection></mx:ArrayCollection></esri:visibleLayers>,这样设置的为空就是不想用来显示只是用来数据查询用。 |
5.还添加了GraphicsLayer对象用来进行高亮显示用,并且为它设置了symbolFunction="{mySymbolFunction}"这样是在mySymbolFunction方法中对点、线、面的显示样式进行设置,代码如啊: |
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--> 1private 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; |
10                        break; |
11                    } |
12                    case Geometry.GEOMETRY_POLYLINE: |
13                    { |
14                        result=sls; |
15                        break; |
16                    } |
17                    case Geometry.GEOMETRY_POLYGON: |
18                    { |
19                        result=sfs; |
20                        break; |
21                    } |
22                } |
23                return result; |
24            } |
对上面的sms、sls、sfs等定义: |
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-->1<esri:SimpleLineSymbol id="sls" style="solid" color="0x0000FF" width="2" alpha="0.6"/> |
2    <esri:SimpleMarkerSymbol id="sms" style="circle" color="0x0000FF" alpha="0.6" size="15"/> |
3    <esri:SimpleFillSymbol id="sfs" color="0x0000FF" alpha="0.6"/> |
6.接下来在页面上添加一个TextInput、Button、mxataGrid分别为查询语句输入框、查询按钮、查询结果显示表,具体显示代码如下: |
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-->1<mx:Canvas width="434" height="48" borderStyle="solid" borderThickness="3" borderColor="#D6D7D8" horizontalCenter="-139" verticalCenter="-183"> |
2        <mx:ComboBox id="layerList" x="10" y="10" width="117"></mx:ComboBox> |
3        <mx:TextInput id="qText" x="135" y="10" width="223" enter="doQuery()" text="STATE_NAME like '%a%'"/> |
4        <mx:Button x="366" y="10" label="查询" fontSize="12" height="22" click="doQuery()"/> |
5    </mx:Canvas> |
6<mx:DataGrid  id="resultTable" change="clickHandler(event)"  height="426" borderStyle="solid" borderThickness="3" borderColor="#D6D7D8" horizontalCenter="179" verticalCenter="6" width="188"> |
7    </mx:DataGrid> |
7.上面的代码中为TextInput添加了enter事件用来实现回车后进行调用doQuery()方法进行查询,为Button添加了click事件点击后调用doQuery()方法进行查询。 |
8.要进行Query还需要esriueryTask控件,在页面上添加如下显示代码: |
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-->1<esri:QueryTask id="queryTask" > |
2    <esri:Query id="query" /> |
3    </esri:QueryTask> |
9.doQuery()方法代码如下,具体说明看注解: |
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--> 1private function doQuery():void |
 2            { |
 3                //清除原来的高亮显示 |
 4                myGraphicsLayer.clear(); |
 5                //设置queryTask的url,就是设置要查询的图层 |
 6                queryTask.url="http://jh-53a435fbc0e8/ArcGIS/rest/services/USA/MapServer/"+layerList.value; |
 7                //queryTask.query.text=qText.text; |
 8 //queryTask.query.where="STATE_NAME like '%"+qText.text+"%'"; |
 9 //设置查询语句 |
10                queryTask.query.where=qText.text; |
11                //查询结果是否返回Geometry |
12                queryTask.query.returnGeometry=true; |
13                queryTask.query.spatialRelationship="esriSpatialRelEnvelopeIntersects"; |
14                //设置要查询的字段 |
15 var fields:Array=new Array(); |
16                fields.push("OBJECTID"); |
17                fields.push("STATE_NAME"); |
18                fields.push("POP2000"); |
19                queryTask.query.outFields=fields;  |
20                //进行查询成功调用onResult方法,错误失败调用onFault |
21                queryTask.execute(query,new AsyncResponder(onResult,onFault)); |
22            } |
23             |
24            //查询成功活进行高亮显示已经数据Grid显示 |
25            private function onResult(featureSet:FeatureSet,token:Object = null):void |
26            { |
27                var resultlist:Array=new Array(); |
28                for each(var griphic:Graphic in featureSet.features) |
29                { |
30                    myGraphicsLayer.add(griphic); |
31                    resultlist.push({"ID":griphic.attributes.OBJECTID,"STATE_NAME":griphic.attributes.STATE_NAME}) |
32                } |
33                //Grid设置数据源进行查询结果显示 |
34                resultTable.dataProvider=resultlist; |
35            } |
36             |
37            //查询失败提示 |
38            private function onFault(info:Object, token:Object = null ):void |
39            { |
40                //Alert.show(info.toString()); |
41                Alert.show("输入的查询语句不正确!"); |
42            } |
10.更加查询语句查询到结果显示到Grid中后还需要实现一个点击Grid的行进行地图定位的功能,上面添加Grid的时候已经为它添加了change事件就是点击某一行后调用clickHandler(event)方法进行定位功能,代码说明如下: |
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--> 1//Grid点击事件进行对点击对象进行定位居中显示 |
 2            public function clickHandler(eventistEvent):void |
 3            { |
 4                //获取点击行的id |
 5 var idstr:String=event.itemRenderer.data.ID; |
 6                //设置查询的图层 |
 7                queryTask.url="http://jh-53a435fbc0e8/ArcGIS/rest/services/USA/MapServer/"+layerList.value; |
 8                //是否返回Geometry |
 9                queryTask.query.returnGeometry=true; |
10                queryTask.query.spatialRelationship="esriSpatialRelEnvelopeIntersects"; |
11                //查询语句 |
12                queryTask.query.where="OBJECTID="+idstr; |
13                //执行查询 |
14                queryTask.execute(query,new AsyncResponder(onResult2,onFault2)); |
15            } |
16             |
17            private function onResult2(featureSet:FeatureSet,token:Object = null):void |
18            { |
19                var resultlist:Array=new Array(); |
20                for each(var griphic:Graphic in featureSet.features) |
21                { |
22                    myGraphicsLayer.add(griphic); |
23                    var geo:Geometry= griphic.geometry; |
24                    var ex:Extent=new Extent(); |
25                    switch(geo.type) |
26                    { |
27                        //点对象 |
28 case Geometry.GEOMETRY_POINT: |
29                        { |
30                            //转成MapPoint |
31 var pnt :MapPoint = geo as MapPoint ; |
32                            //定位中心 |
33                            myMap.centerAt(pnt); |
34                            break; |
35                        } |
36                        //线对象 |
37 case Geometry.GEOMETRY_POLYLINE: |
38                        { |
39                            //转成Polyline |
40 var plineolyline=geo as olyline; |
41                            //设置地图视图范围 |
42                            ex=pline.extent; |
43                            myMap.extent=ex; |
44                            break; |
45                        } |
46                        //面对象 |
47 case Geometry.GEOMETRY_POLYGON: |
48                        { |
49                            //转成Polygon |
50 var pgon:Polygon=geo as Polygon; |
51                            //设置地图视图范围 |
52                            ex=pgon.extent; |
53                            myMap.extent=ex; |
54                            break; |
55                        } |
56                    } |
57 |
58                    break; |
59                } |
60       |
61            } |
62             |
63            private function onFault2(info:Object, token:Object = null ):void |
64            { |
65                Alert.show("出差啦!"); |
66            } |
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