Openlayers示例11 | CartoDB source example

CartoDB source example
匿名地图

两个图层，一个是底图，另外一个图层是根据条件查询显示地图范围。

<!DOCTYPE html>
<html lang="zn">

<head>
  <meta charset="UTF-8">
  <!-- 引入OpenLayers CSS样式 -->
  <link rel="stylesheet"
    href="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v6.13.0/css/ol.css">
  <!-- 引入OpenLayers JS库 -->
  <script src="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v6.13.0/build/ol.js"></script>
  <!-- css代码 -->
  <style>
    .map {
      width: 100%;
      height: 500px;
    }
  </style>
  <title>CartoDB source example</title>
</head>
<body>
  <div class="row-fluid">
    <div class="span12">
      <div id="map" class="map"></div>
      <div>
      <form class="form-horizontal">
        <label>
          Show countries larger than
          <select id="country-area" class="form-control">
            <option value="0" default>0 ㎢</option>
            <option value="5000">5000 ㎢</option>
            <option value="10000">10000 ㎢</option>
            <option value="50000">50000 ㎢</option>
            <option value="100000">100000 ㎢</option>
          </select>
        </label>
      </form>
    </div>
  </div>
</body>
<script>
  const mapConfig = {
  'layers': [
    {
      'type': 'cartodb',
      'options': {
        'cartocss_version': '2.1.1',
        'cartocss': '#layer { polygon-fill: #F00; }',
        'sql': 'select * from european_countries_e where area > 0',
      },
    },
  ],
};

const cartoDBSource = new ol.source.CartoDB({
  account: 'documentation',
  config: mapConfig,
});

const map = new ol.Map({
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM(),
    }),
    new ol.layer.Tile({
      source: cartoDBSource,
    }),
  ],
  target: 'map',
  view: new ol.View({
    center: [0, 0],
    zoom: 2,
  }),
});

function setArea(n) {
  mapConfig.layers[0].options.sql =
    'select * from european_countries_e where area > ' + n;
  cartoDBSource.setConfig(mapConfig);
}

document.getElementById('country-area').addEventListener('change', function () {
  setArea(this.value);
});
</script>
</html>
posted @ 2022-03-23 09:41  槑孒  阅读(68)  评论(0)    收藏  举报