Select Feature

<!--
  示例：要素选中高亮
  要点：ol.interaction.Select 用独立样式覆盖命中要素，并读取选择集
  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>要素选中高亮</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:10px;align-items:center;font-size:12px;color:#58606e;flex-wrap:wrap}
  .bar button{font:inherit;font-size:12px;padding:4px 9px;border:1px solid #ccd1d9;
       border-radius:4px;background:#fff;color:#16181d;cursor:pointer}
  .bar button:hover{background:#eef0f3}
  #map{flex:1 1 auto;min-height:0;background:#eef0f3}
</style>
</head>
<body>
<div class="bar">
  <span id="info">单击任意站点查看名称</span>
  <button id="clear">清空选择</button>
</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 data = [
    [116.310, 39.908, '西单'],
    [116.391, 39.907, '天安门'],
    [116.404, 39.915, '王府井'],
    [116.442, 39.935, '东直门'],
    [116.485, 39.908, '国贸'],
    [116.460, 39.890, '双井'],
    [116.360, 39.930, '平安里'],
    [116.330, 39.960, '积水潭'],
    [116.420, 39.870, '天坛'],
    [116.470, 39.960, '三元桥']
  ];

  var source = new ol.source.Vector({
    features: data.map(function (d) {
      return new ol.Feature({
        name: d[2],
        geometry: new ol.geom.Point(fromLonLat([d[0], d[1]]))
      });
    })
  });

  var layer = new ol.layer.Vector({
    source: source,
    style: new ol.style.Style({
      image: new ol.style.Circle({
        radius: 6,
        fill: new ol.style.Fill({ color: '#1f5fd0' }),
        stroke: new ol.style.Stroke({ color: '#ffffff', width: 2 })
      }),
      text: new ol.style.Text({
        text: '',
        offsetY: -14,
        font: '500 12px sans-serif',
        fill: new ol.style.Fill({ color: '#16181d' }),
        stroke: new ol.style.Stroke({ color: '#ffffff', width: 3 })
      })
    })
  });

  /* 选中态样式单独定义，Select 只在渲染时套用，不改要素自身样式 */
  var selectStyle = new ol.style.Style({
    image: new ol.style.Circle({
      radius: 9,
      fill: new ol.style.Fill({ color: '#d0453a' }),
      stroke: new ol.style.Stroke({ color: '#ffffff', width: 3 })
    }),
    text: new ol.style.Text({
      text: '',
      offsetY: -18,
      font: '600 13px sans-serif',
      fill: new ol.style.Fill({ color: '#8f2319' }),
      stroke: new ol.style.Stroke({ color: '#ffffff', width: 3 })
    })
  });

  /* 让标注始终显示当前选中要素的名称 */
  var select = new ol.interaction.Select({
    layers: [layer],
    style: function (feature) {
      var s = selectStyle.clone();
      s.getText().setText(feature.get('name'));
      return s;
    }
  });

  var map = new ol.Map({
    target: 'map',
    layers: [
      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'}) }),
      layer
    ],
    view: new ol.View({
      center: fromLonLat([116.400, 39.915]),
      zoom: 12
    })
  });

  map.addInteraction(select);

  var info = document.getElementById('info');

  select.on('select', function (evt) {
    var picked = evt.selected;

    if (!picked.length) {
      info.textContent = '单击任意站点查看名称';
      return;
    }

    var names = picked.map(function (f) { return f.get('name'); });
    info.textContent = '已选中 ' + names.length + ' 个：' + names.join('、');
  });

  document.getElementById('clear').addEventListener('click', function () {
    select.getFeatures().clear();
    info.textContent = '单击任意站点查看名称';
  });
})();
</script>
</body>
</html>