查询---QueryTask空间查询

1. 效果图

2. QueryTask属性查询和空间查询的不同

引入模块不同
空间查询多了"esri/toolbars/draw",模块

条件格式

//定义一个绘图工具
var toolBar = new Draw(map);
//给button绑定事件
on(dom.byId("Btn"),"click",function(){    
    //激活绘图工具，我要绘制一个面图形
    toolBar.activate(Draw.POLYGON);
})
on(toolBar, "draw-complete", function (result) {
    //获得绘图得到的面
    var geometry=result.geometry;
    //关闭绘图工具
    toolBar.deactivate();
    queryGraphic(geometry);
});

查询条件

属性查询

    //查询条件，类似于sql语句的where子句
    query.where = "FID = 2";

**空间查询**

    //空间查询的几何对象
    query.geometry = geometry;

3. 贴代码

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title>QueryTask</title>
    <link rel="stylesheet" href="https://js.arcgis.com/3.28/esri/css/esri.css"/>
    <link rel="stylesheet" href="https://js.arcgis.com/3.28/dijit/themes/tundra/tundra.css"/>
    <script  type="text/Javascript" src="https://js.arcgis.com/3.28/"></script>
    <style type="text/css">
        .MapClass{
            width:100%;
            height:800px;
            border:1px solid #000;
        }
    </style>
    <script type="text/javascript">

        require(["esri/map",
            "esri/layers/ArcGISDynamicMapServiceLayer",
            "dojo/dom",
            "dojo/on",
            "esri/tasks/QueryTask",
            "esri/toolbars/draw",
            "esri/tasks/query",
            "esri/symbols/SimpleLineSymbol",
            "esri/symbols/SimpleFillSymbol", 
            "esri/graphic",
            "dojo/domReady!"],
            function (Map, ArcGISDynamicMapServiceLayer,dom, on,
            QueryTask, Draw, Query,
            SimpleLineSymbol,SimpleFillSymbol,Graphic) {
            var map = new Map("mapdiv");
            var layer = new ArcGISDynamicMapServiceLayer
            ("http://localhost:6080/arcgis/rest/services/ecology/beijing_2012_3/MapServer");
            map.addLayer(layer)



            //定义一个绘图工具
            var toolBar = new Draw(map);
            //给button绑定事件
            on(dom.byId("Btn"),"click",function(){    
                //激活绘图工具，我要绘制一个面图形
                toolBar.activate(Draw.POLYGON);
            })
            on(toolBar, "draw-complete", function (result) {
                //获得绘图得到的面
                var geometry=result.geometry;
                //关闭绘图工具
                toolBar.deactivate();
                queryGraphic(geometry);
            });

            function queryGraphic(geometry) {
                //创建查询对象
                var queryTask = new QueryTask( "http://localhost:6080/arcgis/rest/services/ecology/beijing_2012_3/MapServer/0");
                //创建查询参数对象
                var query = new Query();
                //是否返回几何形状
                query.returnGeometry = true;
                //空间查询的几何对象
                query.geometry = geometry;
                //服务器给我们返回的字段信息，*代表返回所有字段
                query.outFields = ["*"];
                //空间参考信息
                query.outSpatialReference = map.spatialReference;
                //查询的标准，此处代表和geometry相交的图形都要返回
                query.spatialRelationship = Query.SPATIAL_REL_INTERSECTS;

                //执行空间查询
                queryTask.execute(query, showQueryResult);
            }




            function showQueryResult(queryResult) {
                //创建线符号
                var lineSymbol=new SimpleLineSymbol(SimpleLineSymbol.STYLE_DASH, new dojo.Color([255, 0, 0]), 3);
                //创建面符号
                var fill=new SimpleFillSymbol(SimpleFillSymbol.STYLE_SOLID, lineSymbol);
                if (queryResult.features.length == 0) {
                    dom.byId("divShowResult").innerHTML = "";
                    return;
                }
                var htmls = "";
                if (queryResult.features.length >= 1) {
                    htmls = htmls + "<table style=\"width: 100%\">";
                    htmls = htmls + "<tr><td>名称</td></tr>";
                    for (var i = 0; i < queryResult.features.length; i++) {
                        //得到graphic
                        var graphic = queryResult.features[i];
                        //给图形赋予符号
                        graphic.setSymbol(fill);
                        //添加到地图从而实现高亮效果
                        map.graphics.add(graphic);
                        ////获得内容，对应属性表
                        var ptName = graphic.attributes["NL_NAME_3"];
                        if (i % 2 == 0)
                            htmls = htmls + "<tr>";
                        else
                            htmls = htmls + "<tr bgcolor=\"#F0F0F0\">";
                        htmls = htmls + "<td><a href=\"#\"\">" + ptName + "</a></td>";
                        htmls = htmls + "</tr>";
                    }
                    htmls = htmls + "</table>";
                    //将教学楼的名称信息和divShowResult绑定
                    dom.byId("divShowResult").innerHTML = htmls;
                }
            }
        });


    </script>
</head>
<body>
    <div id="mapdiv" class="MapClass"></div>
    <input type="button" value="空间查询" id="Btn"/>
    <div id="divShowResult"></div>
</body>
</html>