Select Hover Features

<!--
  示例：悬停高亮
  要点：pointermove 加 forEachFeatureAtPixel 做命中检测，移出后恢复原样式
  依赖：OpenLayers 10.3.1 · jsDelivr CDN（底图 OSM，无 Key）
-->
<!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>悬停高亮</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;color:#16181d}
  .bar{flex:0 0 auto;padding:8px 12px;background:#f6f7f9;border-bottom:1px solid #e3e6ea;
       display:flex;gap:14px;align-items:center;font-size:12px;color:#58606e;flex-wrap:wrap}
  .bar b{color:#16181d;font-weight:600}
  #map{flex:1 1 auto;min-height:0;background:#eef0f3}
</style>
</head>
<body>
<div class="bar">
  <span>悬停对象 <b id="nm">—</b></span>
  <span>编号 <b id="id">—</b></span>
  <span>容差 6 像素</span>
</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 (!window.ol) {
    document.getElementById('map').textContent = 'OpenLayers 加载失败，请检查 cdn.jsdelivr.net 是否可访问';
    return;
  }

  var feats = [];
  for (var i = 0; i < 8; i++) {
    var lon = 116.34 + (i % 4) * 0.045;
    var lat = 39.90 + Math.floor(i / 4) * 0.05;
    feats.push(new ol.Feature({
      geometry: new ol.geom.Point(ol.proj.fromLonLat([lon, lat])),
      name: '点位 ' + (i + 1),
      code: 'N-' + String(101 + i)
    }));
  }

  var normal = new ol.style.Style({
    image: new ol.style.Circle({
      radius: 7,
      fill: new ol.style.Fill({ color: '#1f5fd0' }),
      stroke: new ol.style.Stroke({ color: '#fff', width: 2 })
    })
  });

  var hover = new ol.style.Style({
    image: new ol.style.Circle({
      radius: 10,
      fill: new ol.style.Fill({ color: '#f0a020' }),
      stroke: new ol.style.Stroke({ color: '#fff', width: 3 })
    }),
    text: new ol.style.Text({
      text: '',
      offsetY: -18,
      font: '600 12px sans-serif',
      fill: new ol.style.Fill({ color: '#16181d' }),
      stroke: new ol.style.Stroke({ color: '#fff', width: 3 })
    })
  });

  var layer = new ol.layer.Vector({
    source: new ol.source.Vector({ features: feats }),
    style: normal
  });

  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: ol.proj.fromLonLat([116.41, 39.925]), zoom: 12 }),
    controls: ol.control.defaults.defaults({ attribution: false, rotate: false })
  });

  var current = null;

  function restore() {
    if (current) {
      current.setStyle(null);
      current = null;
      document.getElementById('nm').textContent = '—';
      document.getElementById('id').textContent = '—';
    }
  }

  map.on('pointermove', function (evt) {
    if (evt.dragging) return;
    var hit = null;
    map.forEachFeatureAtPixel(evt.pixel, function (f) { hit = f; return true; }, {
      hitTolerance: 6
    });

    if (hit === current) return;
    restore();
    if (hit) {
      current = hit;
      hit.setStyle(new ol.style.Style({
        image: hover.getImage(),
        text: new ol.style.Text({
          text: hit.get('name'),
          offsetY: -18,
          font: '600 12px sans-serif',
          fill: new ol.style.Fill({ color: '#16181d' }),
          stroke: new ol.style.Stroke({ color: '#fff', width: 3 })
        })
      }));
      document.getElementById('nm').textContent = hit.get('name');
      document.getElementById('id').textContent = hit.get('code');
      map.getTargetElement().style.cursor = 'pointer';
    } else {
      map.getTargetElement().style.cursor = '';
    }
  });

  map.on('mouseout', restore);
})();
</script>
</body>
</html>