ArcGIS api for javascript——查找任务-在地图上查找要素

描述

本例展示了如何使用查找任务搜索数据。本例在地图上用图表显示结果并用 DojoX的grid格式化结果为表格样式。

FindTask构造函数需要一个ArcGIS Server地图服务的URL。本例使用ESRI sample server上的ESRI_StatesCitiesRivers_USA服务。

findTask = new esri.tasks.FindTask("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer");

FindParameters指出哪些图层和字段将被搜索。如果多个图层包含相同的字段名称（例如"NAME"）两个字段都要被搜索。注意 returnGeometry被设置为true以便结果能被显示在地图上。

findParams = new esri.tasks.FindParameters();

findParams.returnGeometry = true;

findParams.layerIds = [0,1,2];

findParams.searchFields = ["CITY_NAME","NAME","SYSTEM","STATE_ABBR","STATE_NAME"];

FindParameters的searchText参数是任务将要搜索什么。这个文本来自输入框并且当单击Find按钮时被发送到execute函数。这行代码执行任务:

findTask.execute(findParams,showResults);

当任务执行结束，showResults函数循环访问FindResult里的graphics数组并增加每个图形到地图。函数也增加每个结果的属性到表格。

注意: ArcGIS JavaScript API的版本1.2使用Dojo 1.2，这有一个改良的表格DataGrid。如果移植应用到ArcGIS JavaScript API 1.2并且想要在本例中继续使用旧版的表格，在代码中查找这行:

dojo.require("dojox.grid._data.model");

修改为:

dojo.require("dojox.grid.compat._data.model");

  1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
  2 <html>
  3   <head>
  4     <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
  5     <meta http-equiv="X-UA-Compatible" content="IE=7" />
  6     <title>Find Task</title>
  7     <style type="text/css">
  8       @import "http://serverapi.arcgisonline.com/jsapi/arcgis/1.5/js/dojo/dijit/themes/tundra/tundra.css";
  9       @import "http://serverapi.arcgisonline.com/jsapi/arcgis/1.5/js/dojo/dojox/grid/compat/_grid/Grid.css";
 10       @import "http://serverapi.arcgisonline.com/jsapi/arcgis/1.5/js/dojo/dojox/grid/compat/_grid/tundraGrid.css";
 11       body { font-size: 0.9em;
 12                font-family: Geneva, Arial, Helvetica, sans-serif;
 13              }
 14         .heading { font-weight: bold;
 15                    padding-bottom: 0.25em;
 16                  }
 17        #grid { border: 1px solid #333;
 18                  width: 33em;
 19                  height: 30em;
 20              }
 21     </style>
 22     <script type="text/javascript">djConfig={parseOnLoad:true}</script>
 23     <script type="text/javascript" src="http://serverapi.arcgisonline.com/jsapi/arcgis/?v=1.5"></script>
 24     <script type="text/javascript" language="Javascript">
 25       dojo.require("dojox.grid.Grid");
 26       dojo.require("dojox.grid.compat._data.model");  //Because of changes in the Dojo data grid and model you must load the comapt_data.model if using version 1.3.
 27       dojo.require("esri.map");
 28       dojo.require("esri.tasks.find");
 29 
 30       var findTask, findParams, map;
 31 
 32       function init() {
 33           map = new esri.Map("map");
 34           var censusMapLayer = new esri.layers.ArcGISDynamicMapServiceLayer("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer", {id:"usa"});
 35           map.addLayer(censusMapLayer);
 36 
 37           //实例化FindTask
 38           findTask = new esri.tasks.FindTask("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer");
 39           //FindTask的参数
 40           findParams = new esri.tasks.FindParameters();
 41           //返回Geometry
 42           findParams.returnGeometry = true;
 43           //查询的图层id
 44           findParams.layerIds = [0,1,2];     
 45           //查询字段
 46           findParams.searchFields = ["CITY_NAME","NAME","SYSTEM","STATE_ABBR","STATE_NAME"];
 47 
 48       }
 49 
 50       //根据输入的关键字进行findTask操纵
 51       function execute(searchText) {
 52         //set the search text to find parameters
 53         findParams.searchText = searchText;
 54         findTask.execute(findParams,showResults);
 55       }
 56       //显示findTask的结果
 57       function showResults(results) {
 58        
 59        //清除上一次的高亮显示
 60         map.graphics.clear();
 61         var dataForGrid = [];
 62 
 63         for (var i=0, j=results.length; i<j; i++) {
 64           var curFeature = results[i];
 65           var graphic = curFeature.feature;
 66           
 67           //把查询到的字段信息等插入到dataForGrid
 68           var layerName = curFeature.layerName;
 69           var layerId = curFeature.layerId;
 70           var foundFieldName = curFeature.foundFieldName;
 71           var foundFieldValue = graphic.attributes[foundFieldName];
 72            
 73           var attValues = [layerName,layerId,foundFieldName,foundFieldValue];
 74           dataForGrid.push(attValues);
 75           //根据类型设置显示样式
 76           switch (graphic.geometry.type) {
 77             case "point":
 78               var symbol = new esri.symbol.SimpleMarkerSymbol(esri.symbol.SimpleMarkerSymbol.STYLE_SQUARE, 10, new esri.symbol.SimpleLineSymbol(esri.symbol.SimpleLineSymbol.STYLE_SOLID, new dojo.Color([255,0,0]), 1), new dojo.Color([0,255,0,0.25]));
 79               break;
 80             case "polyline":
 81               var symbol = new esri.symbol.SimpleLineSymbol(esri.symbol.SimpleLineSymbol.STYLE_DASH, new dojo.Color([255,0,0]), 1);
 82               break;
 83             case "polygon":
 84               var symbol = new esri.symbol.SimpleFillSymbol(esri.symbol.SimpleFillSymbol.STYLE_NONE, new esri.symbol.SimpleLineSymbol(esri.symbol.SimpleLineSymbol.STYLE_DASHDOT, new dojo.Color([255,0,0]), 2), new dojo.Color([255,255,0,0.25]));
 85               break;
 86           }
 87           //设置显示样式
 88           graphic.setSymbol(symbol);
 89           //添加到graphics进行高亮显示
 90           map.graphics.add(graphic);
 91         }
 92 
 93         var model = new dojox.grid.data.Table(null, dataForGrid);
 94 
 95         var view1 = {
 96           cells: [
 97             [{name: 'Layer Name'},{name: 'Layer ID'},{name: 'Found Field Name'},{name: 'Found Field Value'}]
 98           ]
 99         };
100 
101         var layout = [ view1 ];
102         gridWidget.setModel(model);
103         gridWidget.setStructure(layout);
104 
105       }
106 
107       dojo.addOnLoad(init);
108     </script>
109   </head>
110   <body class="tundra">
111     <div class="heading">Find State/City/River: <input type="text" id="searchText" value="KS" />
112     <input type="button" value="Find" onclick="execute(dojo.byId('searchText').value);" /></div>
113     <div id="map" style="400px; height:300px; border:1px solid #000;"></div>
114     <div id="grid" dojoType="dojox.Grid" jsId="gridWidget" structure="layout"></div>
115   </body>
116 </html>