Custom Interactions

<!--
  说明：自定义交互的中文示例，数据在页面内生成，可独立运行。
  核心逻辑：new ol.interaction.Pointer({handleDownEvent, handleDragEvent, handleUpEvent})
  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>自定义交互</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;flex-wrap:wrap;font-size:12px;color:#58606e}
  .bar label{display:flex;gap:5px;align-items:center;cursor:pointer}
  .bar button{font:inherit;padding:3px 9px;border:1px solid #c9ced6;background:#fff;
       border-radius:5px;cursor:pointer;color:#333}
  .bar button:hover{background:#eef2f8}
  .bar input[type=range]{width:110px;vertical-align:middle}
  .bar input[type=text]{font:inherit;padding:2px 6px;border:1px solid #c9ced6;border-radius:4px}
  #map{flex:1 1 auto;min-height:0;background:#eef0f3;position:relative}
  .panel{flex:0 0 auto;max-height:34%;overflow:auto;padding:8px 12px;font-size:12px;
       background:#fff;border-top:1px solid #e3e6ea;color:#3d4451}
  .panel pre{margin:0;font-family:Consolas,"Courier New",monospace;font-size:11px;
       white-space:pre-wrap;word-break:break-all;line-height:1.5}
  .ol-attribution{font-size:11px}

</style>
</head>
<body>
<div class="bar">
<span>按住任意标记拖动</span>
<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') {
    var errBox = document.getElementById('map');
    if (errBox) {
      errBox.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 places = [
    [116.35, 39.93, '标记 A'],
    [116.43, 39.90, '标记 B'],
    [116.39, 39.86, '标记 C'],
    [116.47, 39.95, '标记 D']
  ];

  var features = places.map(function (p) {
    return new ol.Feature({
      geometry: new ol.geom.Point(fromLonLat([p[0], p[1]])),
      name: p[2]
    });
  });

  var layer = new ol.layer.Vector({
    source: new ol.source.Vector({features: features}),
    style: new ol.style.Style({
      image: new ol.style.Circle({
        radius: 8,
        fill: new ol.style.Fill({color: '#1f5fd0'}),
        stroke: new ol.style.Stroke({color: '#ffffff', width: 2})
      }),
      text: new ol.style.Text({
        text: '',
        offsetY: -18,
        font: '500 12px sans-serif',
        fill: new ol.style.Fill({color: '#16181d'}),
        stroke: new ol.style.Stroke({color: '#ffffff', width: 3})
      })
    })
  });

  layer.setStyle(function (feature) {
    return new ol.style.Style({
      image: new ol.style.Circle({
        radius: 8,
        fill: new ol.style.Fill({color: '#1f5fd0'}),
        stroke: new ol.style.Stroke({color: '#ffffff', width: 2})
      }),
      text: new ol.style.Text({
        text: feature.get('name'),
        offsetY: -18,
        font: '500 12px sans-serif',
        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([116.41, 39.91]), zoom: 12}),
    controls: ol.control.defaults.defaults({attribution: false, zoom: true, rotate: false})
  });

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

  var dragMarker = new ol.interaction.Pointer({
    handleDownEvent: function (evt) {
      var hit = map.forEachFeatureAtPixel(evt.pixel, function (f) { return f; }, {hitTolerance: 8});
      if (!hit) { return false; }
      dragging = hit;
      info.textContent = '开始拖动 ' + hit.get('name');
      return true;
    },
    handleDragEvent: function (evt) {
      if (!dragging) { return; }
      dragging.getGeometry().setCoordinates(evt.coordinate);
    },
    handleUpEvent: function () {
      if (!dragging) { return false; }
      var c = ol.proj.toLonLat(dragging.getGeometry().getCoordinates());
      info.textContent = dragging.get('name') + ' 移到 ' + c[0].toFixed(4) + ', ' + c[1].toFixed(4);
      dragging = null;
      return false;
    }
  });

  map.addInteraction(dragMarker);
})();
</script>
</body>
</html>