Cluster creation in openlayer 6.4.3 - Uncaught TypeError: this.source.loadFeatures is not a function

Question

我正在尝试使用 ol 6.4.3 创建集群。我的剧本是

var cluster_data = {
            "type": "Feature",
          'features': [
            {
              'type': 'Feature',
              'geometry': {
                'type': 'Point',
                'coordinates': [686213.47091037, 1093486.3776117],
              },
            },
            {
              'type': 'Feature',
              'geometry': {
                'type': 'Point',
                'coordinates': [687067.04391223, 1094462.7275206],
              },
            },
            {
              'type': 'Feature',
              'geometry': {
                'type': 'Point',
                'coordinates': [687214.60645801, 1094362.868384],
              },
            }

            ],
        };
var features = new Array(3);
 var source = new ol.layer.Vector({
          features: new ol.format.GeoJSON().readFeatures(cluster_data),
});

var clusterSource = new ol.source.Cluster({
  distance: 40,
  source: source,
});

var styleCache = {};
var clusters = new ol.layer.Vector({
  source: clusterSource,
  style: function (feature) {
    var size = feature.get('features').length;
    var style = styleCache[size];
    if (!style) {
      style = new Style({
        image: new CircleStyle({
          radius: 10,
          stroke: new Stroke({
            color: '#fff',
          }),
          fill: new Fill({
            color: '#3399CC',
          }),
        }),
        text: new Text({
          text: size.toString(),
          fill: new Fill({
            color: '#fff',
          }),
        }),
      });
      styleCache[size] = style;
    }
    return style;
  },
});
map.addLayer(clusters);

我添加了其他 3 个 Tile 层 map.getLayers().extend([bm,road,landmark]); 并尝试在其上添加集群。但是出现错误 Uncaught TypeError: this.source.loadFeatures is not a function while adding cluster.

添加图层后得到的地图是

Answer 1

错误是因为

var source = new ol.layer.Vector({

应该是

var source = new ol.source.Vector({

另外，特征之前的数据中的第一个类型应该是

"type": "FeatureCollection",

如果您使用的是 OpenLayers 完整版本 new Style new CircleStyle new Stroke new Fill 和 new Text 应该 new ol.style.Style new ol.style.Circle new ol.style.Stroke new ol.style.Fill 和 new ol.style.Text

<!DOCTYPE html>
<html>
  <head>
    <link rel="stylesheet" href="https://openlayers.org/en/v6.4.3/css/ol.css" type="text/css">
    <!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
    <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"></script>
    <script src="https://openlayers.org/en/v6.4.3/build/ol.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/proj4js/2.6.1/proj4.js"></script>
    <style>
      html, body, .map {
        margin: 0;
        padding: 0;
        width: 100%;
        height: 100%;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <script>

proj4.defs("EPSG:32643","+proj=utm +zone=43 +datum=WGS84 +units=m +no_defs");
ol.proj.proj4.register(proj4);

var cluster_data = {
          "type": "FeatureCollection",
          'features': [
            {
              'type': 'Feature',
              'geometry': {
                'type': 'Point',
                'coordinates': [686213.47091037, 1093486.3776117],
              },
            },
            {
              'type': 'Feature',
              'geometry': {
                'type': 'Point',
                'coordinates': [687067.04391223, 1094462.7275206],
              },
            },
            {
              'type': 'Feature',
              'geometry': {
                'type': 'Point',
                'coordinates': [687214.60645801, 1094362.868384],
              },
            }

            ],
        };

var source = new ol.source.Vector({
          features: new ol.format.GeoJSON().readFeatures(cluster_data),
});

var clusterSource = new ol.source.Cluster({
  distance: 40,
  source: source,
});

var styleCache = {};
var clusters = new ol.layer.Vector({
  source: clusterSource,
  style: function (feature) {
    var size = feature.get('features').length;
    var style = styleCache[size];
    if (!style) {
      style = new ol.style.Style({
        image: new ol.style.Circle({
          radius: 10,
          stroke: new ol.style.Stroke({
            color: '#fff',
          }),
          fill: new ol.style.Fill({
            color: '#3399CC',
          }),
        }),
        text: new ol.style.Text({
          text: size.toString(),
          fill: new ol.style.Fill({
            color: '#fff',
          }),
        }),
      });
      styleCache[size] = style;
    }
    return style;
  },
});

var map = new ol.Map({
  target: 'map',
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM()
    })
  ],
  view: new ol.View({
    projection: "EPSG:32643"
  })
});

map.addLayer(clusters);

map.getView().fit(source.getExtent());
map.getView().setZoom(map.getView().getZoom() - 6);

    </script>
  </body>
</html>

Cluster creation in openlayer 6.4.3 - Uncaught TypeError: this.source.loadFeatures is not a function

Cluster creation in openlayer 6.4.3 - Uncaught TypeError: this.source.loadFeatures is not a function

cluster-analysis

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