缩放到选定的功能

Question

我正在尝试 select 一个要素，并使用 ArcGIS javascript api.

将地图缩放到该 selected 要素

我已经检查以确保查询 returns 实际结果，因此应该检索到数据。我的脚本基于 FeatureLayer 介绍 - 4.11。代码如下。

<script>
  require([
    "esri/Map",
    "esri/views/MapView",
    "esri/layers/FeatureLayer"
  ], function(Map, MapView, FeatureLayer) {
    var map = new Map({
      basemap: "hybrid"
    });

    var view = new MapView({
      container: "viewDiv",
      map: map,

      extent: {
        // autocasts as new Extent()
        xmin: -9177811,
        ymin: 4247000,
        xmax: -9176791,
        ymax: 4247784,
        spatialReference: 102100
      }
    });

    /********************
     * Add feature layer
     ********************/

    // Carbon storage of trees in Warren Wilson College.
    var featureLayer = new FeatureLayer({
      url:
        "http://someURL/FeatureServer/45"
    });

    map.add(featureLayer);

    const query = new Query();
    query.where = "LASTNAME = 'GLOVER'";
    query.outSpatialReference = { wkid: 102100 };
    query.returnGeometry = true;
    query.outFields = [ "LASTNAME" ];

    featureLayer.queryFeatures(query).then(function(results){
      var newextent = esri.graphicsExtent(results.features);
      map.setExtent(newextent,true);

    });

  });
</script>

我原以为地图会缩放到 selected 多边形的范围，但事实并非如此。没有出现错误消息 - 地图仅显示原始范围。

希望有人能给我指出正确的方向。

Answer 1

将你的行 const query = new Query(); 替换为 const query = featureLayer.createQuery(); 因为你没有在 require 中声明 Query，例如：

require([
  "esri/Map",
  "esri/views/MapView",
  "esri/layers/FeatureLayer",
  "esri/tasks/support/Query"
], function(Map, MapView, FeatureLayer, Query) {

自 ArcGIS Javascript API 版本 4.* 起，您可以从 featureLayer : https://developers.arcgis.com/javascript/latest/api-reference/esri-layers-FeatureLayer.html#createQuery and you control the view with MapView https://developers.arcgis.com/javascript/latest/api-reference/esri-views-MapView.html#goTo :

创建查询

featureLayer.queryFeatures(query).then(function(results){
  const features = results.features;
  view.goTo(features[0].geometry);
});

缩放到选定的功能

zooming to selected features

javascript

arcgis