View Bookmark

<!--
  示例：视角书签
  要点：保存 center / zoom / rotation，animate 恢复，书签按钮动态生成
  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>视角书签</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:8px;align-items:center;font-size:12px;color:#58606e;flex-wrap:wrap}
  .bar button{padding:3px 9px;border:1px solid #cfd4dc;border-radius:4px;
              background:#fff;cursor:pointer;font-size:12px}
  .bar .bm{border-color:#1f5fd0;color:#1f5fd0}
  #map{flex:1 1 auto;min-height:0;background:#eef0f3}
</style>
</head>
<body>
<div class="bar">
  <button id="save">保存视图</button>
  <button id="clear">清空书签</button>
  <span id="list"></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 view = new ol.View({
    center: ol.proj.fromLonLat([116.3974, 39.9093]),
    zoom: 12,
    rotation: 0
  });

  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'}) })],
    view: view,
    controls: ol.control.defaults.defaults({ attribution: false })
  });

  var listEl = document.getElementById('list');
  var bookmarks = [];

  function save() {
    var center = view.getCenter();
    var zoom = view.getZoom();
    var rotation = view.getRotation();

    bookmarks.push({ center: center, zoom: zoom, rotation: rotation });

    var btn = document.createElement('button');
    btn.className = 'bm';
    btn.type = 'button';
    btn.textContent = '书签 ' + bookmarks.length + ' · z' + zoom.toFixed(1);

    var item = bookmarks[bookmarks.length - 1];
    btn.addEventListener('click', function () {
      view.animate({
        center: item.center,
        zoom: item.zoom,
        rotation: item.rotation,
        duration: 700
      });
    });

    listEl.appendChild(btn);
  }

  document.getElementById('save').addEventListener('click', save);

  document.getElementById('clear').addEventListener('click', function () {
    bookmarks = [];
    listEl.innerHTML = '';
  });
})();
</script>
</body>
</html>