Kml Earthquakes

<!--
  说明：KML 地震数据
  核心逻辑：ol.format.KML 解析内联 KML，dataProjection 4326 转 featureProjection 3857
  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>KML 地震数据</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;padding:4px 10px;border:1px solid #c9d0da;border-radius:5px;
              background:#fff;color:#1f2a37;cursor:pointer}
  #info{margin-left:auto}
  #map{flex:1 1 auto;min-height:0;background:#eef0f3}
</style>
</head>
<body>
<div class="bar">
  <span>数据来源：页面内联 KML 字符串</span>
  <button id="again">重新解析</button>
  <span id="info">—</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 kml = '<?xml version="1.0" encoding="UTF-8"?>' +
    '<kml xmlns="http://www.opengis.net/kml/2.2"><Document>' +
    '<Placemark><name>汶川 6.1</name><description>mag=6.1</description>' +
    '<Point><coordinates>103.40,31.00,0</coordinates></Point></Placemark>' +
    '<Placemark><name>芦山 5.6</name><description>mag=5.6</description>' +
    '<Point><coordinates>102.98,30.30,0</coordinates></Point></Placemark>' +
    '<Placemark><name>九寨沟 5.2</name><description>mag=5.2</description>' +
    '<Point><coordinates>103.90,33.20,0</coordinates></Point></Placemark>' +
    '<Placemark><name>玉树 4.8</name><description>mag=4.8</description>' +
    '<Point><coordinates>97.00,33.10,0</coordinates></Point></Placemark>' +
    '<Placemark><name>鲁甸 4.3</name><description>mag=4.3</description>' +
    '<Point><coordinates>103.30,27.10,0</coordinates></Point></Placemark>' +
    '<Placemark><name>康定 3.9</name><description>mag=3.9</description>' +
    '<Point><coordinates>101.90,30.00,0</coordinates></Point></Placemark>' +
    '</Document></kml>';

  var format = new ol.format.KML();

  var source = new ol.source.Vector();

  var layer = new ol.layer.Vector({
    source: source,
    style: function (feature) {
      var desc = feature.get('description') || '';
      var m = /mag=([\d.]+)/.exec(desc);
      var mag = m ? Number(m[1]) : 4;
      return new ol.style.Style({
        image: new ol.style.Circle({
          radius: 4 + mag * 2,
          fill: new ol.style.Fill({
            color: mag >= 5.5 ? 'rgba(200,40,28,0.85)'
              : mag >= 4.5 ? 'rgba(226,110,40,0.85)' : 'rgba(31,95,208,0.85)'
          }),
          stroke: new ol.style.Stroke({ color: '#ffffff', width: 2 })
        }),
        text: new ol.style.Text({
          text: feature.get('name') || '',
          font: '600 12px sans-serif',
          offsetY: -18,
          fill: new ol.style.Fill({ color: '#16181d' }),
          stroke: new ol.style.Stroke({ color: '#ffffff', width: 3 })
        })
      });
    }
  });

  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([102, 31]), zoom: 5, minZoom: 2, maxZoom: 19 }),
    controls: ol.control.defaults.defaults({ attribution: false, rotate: false })
  });

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

  function load() {
    source.clear();
    var feats = format.readFeatures(kml, {
      dataProjection: 'EPSG:4326',
      featureProjection: 'EPSG:3857'
    });
    source.addFeatures(feats);
    map.getView().fit(source.getExtent(), { padding: [70, 70, 70, 70], duration: 400 });
    info.textContent = '解析到 ' + feats.length + ' 个震中';
  }

  document.getElementById('again').addEventListener('click', load);
  load();
})();
</script>
</body>
</html>