原文链接及内容

原文链接：https://openlayers.org/en/latest/examples/getfeatureinfo-layers.html

运行界面

演示ol/format/WMSGetFeatureInfo格式对象中layers选项的用法，该选项允许单个WMS GetFeatureInfo请求按图层名称读取多个图层并返回要素信息。

main.js代码如下：

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import WMSGetFeatureInfo from 'ol/format/WMSGetFeatureInfo.js';

fetch('data/wmsgetfeatureinfo/osm-restaurant-hotel.xml')
  .then(function (response) {
    return response.text();
  })
  .then(function (response) {
    // this is the standard way to read the features
    const allFeatures = new WMSGetFeatureInfo().readFeatures(response);
    document.getElementById('all').innerText = allFeatures.length.toString();

    // when specifying the 'layers' options, only the features of those
    // layers are returned by the format
    const hotelFeatures = new WMSGetFeatureInfo({
      layers: ['hotel'],
    }).readFeatures(response);
    document.getElementById('hotel').innerText =
      hotelFeatures.length.toString();

    const restaurantFeatures = new WMSGetFeatureInfo({
      layers: ['restaurant'],
    }).readFeatures(response);
    document.getElementById('restaurant').innerText =
      restaurantFeatures.length.toString();
  });

界面布局文件index.html代码如下：

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<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>WMS GetFeatureInfo (Layers)</title>
    <link rel="stylesheet" href="node_modules/ol/ol.css">
    <style>
      .map {
        width: 100%;
        height: 400px;
      }
    </style>
  </head>
  <body>
    <table id="info">
      <tr>
        <td>All features:</td>
        <td id="all"></td>
      </tr>
      <tr>
        <td>Hotel features:</td>
        <td id="hotel"></td>
      </tr>
      <tr>
        <td>Restaurant features:</td>
        <td id="restaurant"></td>
      </tr>
    </table>
    <!-- Pointer events polyfill for old browsers, see https://caniuse.com/#feat=pointer -->
    <script src="https://cdn.jsdelivr.net/npm/elm-pep@1.0.6/dist/elm-pep.js"></script>
    <script type="module" src="main.js"></script>
  </body>
</html>