Dashed Line

<!--
  示例：虚线样式
  要点：Stroke 的 lineDash 数组控制虚实间距，空数组即实线，切换只需 setStyle
  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>虚线样式</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}
  .bar button{padding:4px 10px;border:1px solid #cfd4dc;border-radius:4px;
              background:#fff;cursor:pointer;font-size:12px}
  .bar button.on{background:#1f5fd0;border-color:#1f5fd0;color:#fff}
  #map{flex:1 1 auto;min-height:0;background:#eef0f3}
</style>
</head>
<body>
<div class="bar">
  <button id="long" class="on">长虚线</button>
  <button id="short">短虚线</button>
  <button id="solid">实线</button>
  <span>线段为规划路线，虚线表示未建成</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 (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 routes = [
    [[116.365, 39.902], [116.384, 39.908], [116.402, 39.912], [116.420, 39.920]],
    [[116.372, 39.921], [116.392, 39.918], [116.412, 39.913], [116.431, 39.906]]
  ].map(function (coords) {
    return new ol.Feature({
      geometry: new ol.geom.LineString(coords.map(function (p) {
        return fromLonLat(p);
      }))
    });
  });

  var layer = new ol.layer.Vector({
    source: new ol.source.Vector({ features: routes })
  });

  function makeStyle(dash, width) {
    return new ol.style.Style({
      stroke: new ol.style.Stroke({
        color: '#1f5fd0',
        width: width,
        lineDash: dash,
        lineCap: 'round'
      })
    });
  }

  var presets = {
    long: { dash: [16, 10], width: 3 },
    short: { dash: [5, 5], width: 3 },
    solid: { dash: [], width: 3 }
  };

  function apply(key) {
    var p = presets[key];
    layer.setStyle(makeStyle(p.dash, p.width));
  }

  apply('long');

  ['long', 'short', 'solid'].forEach(function (key) {
    document.getElementById(key).addEventListener('click', function () {
      apply(key);
      Array.prototype.forEach.call(document.querySelectorAll('.bar button'), function (b) {
        b.classList.remove('on');
      });
      this.classList.add('on');
    });
  });

  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([116.398, 39.911]),
      zoom: 13
    }),
    controls: ol.control.defaults.defaults({ attribution: false })
  });
})();
</script>
</body>
</html>