Tile Grid

<!--
  示例：瓦片网格可视化
  要点：getTileRangeForExtentAndZ 取范围，getTileCoordExtent 画每块瓦片边界与编号
  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>瓦片网格可视化</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:12px;align-items:center;font-size:12px;color:#58606e}
  .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="showLabel" checked> 显示编号</label>
  <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 base = 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'}) });
  var grid = base.getSource().getTileGrid();

  var gridSource = new ol.source.Vector();
  var gridLayer = new ol.layer.Vector({ source: gridSource });

  var showLabel = true;

  function buildStyle(feature) {
    return new ol.style.Style({
      stroke: new ol.style.Stroke({ color: 'rgba(194, 65, 12, 0.8)', width: 1 }),
      fill: new ol.style.Fill({ color: 'rgba(194, 65, 12, 0.05)' }),
      text: showLabel ? new ol.style.Text({
        text: feature.get('label'),
        font: '600 10px ui-monospace, Consolas, monospace',
        fill: new ol.style.Fill({ color: '#c2410c' }),
        stroke: new ol.style.Stroke({ color: '#ffffff', width: 3 })
      }) : undefined
    });
  }

  gridLayer.setStyle(buildStyle);

  var view = new ol.View({
    center: ol.proj.fromLonLat([116.3974, 39.9093]),
    zoom: 11
  });

  var map = new ol.Map({
    target: 'map',
    layers: [base, gridLayer],
    view: view,
    controls: ol.control.defaults.defaults({ attribution: false })
  });

  var info = document.getElementById('info');
  var LIMIT = 36;

  function redraw() {
    var extent = view.calculateExtent(map.getSize());
    var z = Math.max(0, Math.min(19, Math.floor(view.getZoom())));
    var range = grid.getTileRangeForExtentAndZ(extent, z);

    gridSource.clear();
    var count = 0;
    var truncated = false;

    for (var y = range.minY; y <= range.maxY; y++) {
      for (var x = range.minX; x <= range.maxX; x++) {
        if (count >= LIMIT) {
          truncated = true;
          break;
        }
        var te = grid.getTileCoordExtent([z, x, y]);
        var ring = [
          [te[0], te[1]], [te[2], te[1]], [te[2], te[3]], [te[0], te[3]], [te[0], te[1]]
        ];
        var f = new ol.Feature({ geometry: new ol.geom.Polygon([ring]) });
        f.set('label', z + '/' + x + '/' + y);
        gridSource.addFeature(f);
        count++;
      }
      if (truncated) {
        break;
      }
    }

    info.textContent = '层级 ' + z + ' · 当前网格 ' + count + ' 块' +
      (truncated ? '（已截断）' : '');
  }

  /* 首帧渲染后才有尺寸，此时再计算覆盖范围 */
  map.once('postrender', redraw);
  map.on('moveend', redraw);

  document.getElementById('showLabel').addEventListener('change', function () {
    showLabel = this.checked;
    gridLayer.setStyle(buildStyle);
  });
})();
</script>
</body>
</html>