Layer Switcher

<!--
  示例：图层切换
  要点：三个底图用单选切换可见性，叠加标注图层独立开关
  依赖：OpenLayers 10.3.1 · jsDelivr CDN
-->
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta name="robots" content="noindex,follow">
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>图层切换</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/ol@10.3.1/ol.css">
<style>
  html,body{height:100%;margin:0}
  body{display:flex;flex-direction:column;overflow:hidden;
       font:13px/1.6 -apple-system,"Segoe UI","PingFang SC",sans-serif}
  .bar{flex:0 0 auto;padding:8px 12px;background:#f6f7f9;border-bottom:1px solid #e3e6ea;
       display:flex;gap:16px;align-items:center;font-size:12px;color:#58606e;flex-wrap:wrap}
  .bar label{display:flex;gap:5px;align-items:center;cursor:pointer}
  .bar .sep{width:1px;height:18px;background:#e3e6ea}
  #map{flex:1 1 auto;min-height:0;background:#eef0f3}
</style>
</head>
<body>
<div class="bar">
  <label><input type="radio" name="base" value="osm" checked> 标准 OSM</label>
  <label><input type="radio" name="base" value="hot"> Humanitarian</label>
  <label><input type="radio" name="base" value="none"> 无底图</label>
  <span class="sep"></span>
  <label><input type="checkbox" id="tglMarker" checked> 站点标注</label>
</div>
<div id="map"></div>
<script src="https://cdn.jsdelivr.net/npm/ol@10.3.1/dist/ol.js"></script>
<script>
(function () {
  'use strict';

  if (typeof ol === 'undefined') {
    document.getElementById('map').innerHTML =
      '<div style="padding:20px;color:#b42318">OpenLayers 加载失败，请检查能否访问 cdn.jsdelivr.net</div>';
    return;
  }

  var fromLonLat = ol.proj.fromLonLat;

  var osmLayer = new ol.layer.Tile({ source: new ol.source.XYZ({url: 'https://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer/tile/{z}/{y}/{x}', attributions: 'Tiles © Esri'}) });

  var hotLayer = new ol.layer.Tile({
    source: new ol.source.XYZ({
      url: 'https://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer/tile/{z}/{y}/{x}',
      attributions: ' Tiles © Esri'
    }),
    visible: false
  });

  var sites = [
    [116.391263, 39.907359, '天安门'],
    [116.410600, 39.914700, '王府井'],
    [116.374200, 39.909700, '西单']
  ].map(function (s) {
    var f = new ol.Feature({
      geometry: new ol.geom.Point(fromLonLat([s[0], s[1]])),
      name: s[2]
    });
    f.setStyle(new ol.style.Style({
      image: new ol.style.Circle({
        radius: 6,
        fill: new ol.style.Fill({ color: '#d0453a' }),
        stroke: new ol.style.Stroke({ color: '#ffffff', width: 2 })
      }),
      text: new ol.style.Text({
        text: s[2],
        offsetY: -15,
        font: '500 12px sans-serif',
        fill: new ol.style.Fill({ color: '#16181d' }),
        stroke: new ol.style.Stroke({ color: '#ffffff', width: 3 })
      })
    }));
    return f;
  });

  var markerLayer = new ol.layer.Vector({
    source: new ol.source.Vector({ features: sites }),
    zIndex: 5
  });

  new ol.Map({
    target: 'map',
    layers: [osmLayer, hotLayer, markerLayer],
    view: new ol.View({
      center: fromLonLat([116.391263, 39.907359]),
      zoom: 13
    })
  });

  var bases = { osm: osmLayer, hot: hotLayer, none: null };

  Array.prototype.forEach.call(
    document.querySelectorAll('input[name=base]'),
    function (radio) {
      radio.addEventListener('change', function () {
        if (!this.checked) return;

        Object.keys(bases).forEach(function (key) {
          if (bases[key]) bases[key].setVisible(key === this.value);
        }, this);
      });
    }
  );

  document.getElementById('tglMarker').addEventListener('change', function () {
    markerLayer.setVisible(this.checked);
  });
})();
</script>
</body>
</html>