利用 Task\Query 实现定位 , FeatureLayer 的属性查询

放纵了几天，又有了学习的动力。今天实现了利用对 FeatureLayer 进行属性查询在地图上进行跳转。

　　一、我下载了一幅浙江省的县界面地图，存在NAME字段，利用Name就能进行查询了：

var name = tb.value;
if(name!="")
{
    var query = new esri.tasks.Query();
    query.where = "NAME = '"+name+"'";
    fl.queryFeatures(query, function (featureset) {
        var a =featureset.features[0].geometry.getExtent();
        map.setExtent(a);
    });
}

　　备注：FeatureLayer.queryFeatures 返回的不是 Feature 的一个集合，需要注意的是它本身就是单独的一个 Object ，而不是单纯的 Arry[] ，一开始没仔细看，半天取不出数据。不知道能不能进行模糊查询，希望可以，不然真的不方便啊。再试试...

　　二、很简单的例子给大家看看：

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title>Query Demo</title>
        <link rel="stylesheet" href="http://js.arcgis.com/3.10/js/dojo/dijit/themes/tundra/tundra.css">
        <link rel="stylesheet" href="http://js.arcgis.com/3.10/js/esri/css/esri.css">
        <script type="text/javascript" charset="utf-8" src="http://js.arcgis.com/3.10/"></script>
        <script type="text/javascript" charset="utf-8" src="js/dojo.js"></script>        
        <script type="text/javascript" charset="utf-8">
          require([
            "esri/map", "esri/layers/FeatureLayer",
            "esri/tasks/query", "esri/TimeExtent","esri/tasks/query",
            "dojo/number", "dojo/date/locale", "dojo/dom","dojo/on",
            "dojo/_base/array", "dojo/store/Memory",
            "dgrid/OnDemandGrid", "dojo/domReady!"
          ], function()
          {
              //初始化地图控件
              var map = new esri.Map("mapdiv");
              map.setBasemap("osm");
            var bounds = new esri.geometry.Extent({
              "xmin":118.363523,"ymin":29.219302,"xmax":119.508848,"ymax":30.073848,
              "spatialReference":{"wkid":4326}});
            map.setExtent(bounds);
            //初始化图层
            var durl = "http...MapServer";
            var dl = new esri.layers.ArcGISDynamicMapServiceLayer(durl);
            var furl = "http...MapServer/0";
            var fl = new esri.layers.FeatureLayer(furl,{outFields: ["*"],opacity: 0});
            map.addLayer(dl);
            map.addLayer(fl);
            //注册Go点击事件
            var btn = document.getElementById("query");
              btn.onclick = function(){
                  var tb = document.getElementById("val");
                    var name = tb.value;
                    if(name!="")
                    {
                        var query = new esri.tasks.Query();
                        query.where = "NAME = '"+name+"'";
                        fl.queryFeatures(query, function (featureset) {
                            var a =featureset.features[0].geometry.getExtent();
                            map.setExtent(a);
                        });
                    }
              }
          });
        </script>
    </head>
    <body>
        <div id="tolbox">
            Name:
            <input type="text" name="val" id="val" />
            <input type="button" name="query" id="query" value="Go" />
        </div>
        <div id="mapdiv" style="width: 600px; height: 600px; background-color: #FF8F8F;"></div>
    </body>
</html>

效果：

                         

posted on 2014-08-05 15:59  Moral  阅读(1415)  评论(0)  编辑  收藏  举报

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