Street Labels

<!--
  示例：街道沿线标注
  要点：LineString 配 Text 的 placement 与 rotation，让文字顺着线条走
  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>街道沿线标注</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 label{display:flex;gap:5px;align-items:center;cursor:pointer}
  #map{flex:1 1 auto;min-height:0;background:#eef0f3}
</style>
</head>
<body>
<div class="bar">
  <label><input type="checkbox" id="rot" checked> 文字随线旋转</label>
  <label><input type="checkbox" id="fill" checked> 沿整条线重复</label>
  <span>拖动地图看标注跟随线段方向</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 ROADS = [
    ['长安街', [[116.300, 39.9075], [116.360, 39.9072], [116.430, 39.9078], [116.500, 39.9082]]],
    ['中轴路', [[116.391, 39.860], [116.393, 39.900], [116.396, 39.940], [116.398, 39.990]]],
    ['朝阳北路', [[116.420, 39.925], [116.470, 39.928], [116.520, 39.930], [116.560, 39.932]]],
    ['西直门外大街', [[116.300, 39.941], [116.340, 39.940], [116.375, 39.938]]]
  ];

  var feats = ROADS.map(function (r) {
    return new ol.Feature({
      geometry: new ol.geom.LineString(
        r[1].map(function (c) { return ol.proj.fromLonLat(c); })
      ),
      name: r[0]
    });
  });

  var rotate = true;
  var repeat = true;

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

  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([116.40, 39.925]), zoom: 12 }),
    controls: ol.control.defaults.defaults({ attribution: false, rotate: false })
  });

  function refresh() {
    layer.setStyle(function (f) {
      return new ol.style.Style({
        stroke: new ol.style.Stroke({ color: '#bfc6d1', width: 7, lineCap: 'round' }),
        text: new ol.style.Text({
          text: f.get('name'),
          font: '500 12px "PingFang SC", sans-serif',
          placement: 'line',
          overflow: true,
          repeat: repeat ? 240 : 0,
          rotateWithView: rotate,
          fill: new ol.style.Fill({ color: '#3b4250' }),
          stroke: new ol.style.Stroke({ color: 'rgba(255,255,255,.9)', width: 4 })
        })
      });
    });
  }

  function bind(id, setter) {
    document.getElementById(id).addEventListener('change', function () {
      setter(this.checked);
      refresh();
    });
  }

  bind('rot', function (v) { rotate = v; });
  bind('fill', function (v) { repeat = v; });
  refresh();
})();
</script>
</body>
</html>