原文链接及内容

原文链接：https://openlayers.org/en/latest/examples/reusable-source.html

运行界面

你可以调用source.seturl()来更新切片数据源的URL。请注意，当更改一个切片数据源的URL时，在加载新切片之前不会替换现有的切片。若要清除当前渲染的切片数据，可以调用source.refresh()方法。另外，如果你想要删除已渲染的切片并开始重载新切片，则可以使用两个单独的数据源。

main.js代码如下：

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import Map from 'ol/Map.js';
import TileLayer from 'ol/layer/Tile.js';
import View from 'ol/View.js';
import XYZ from 'ol/source/XYZ.js';

const key =
  'Your Mapbox access token from https://mapbox.com/ here';
const baseUrl = 'https://{a-c}.tiles.mapbox.com/v4';
const urls = [
  baseUrl + '/mapbox.blue-marble-topo-jan/{z}/{x}/{y}.png?access_token=' + key,
  baseUrl +
    '/mapbox.blue-marble-topo-bathy-jan/{z}/{x}/{y}.png?access_token=' +
    key,
  baseUrl + '/mapbox.blue-marble-topo-jul/{z}/{x}/{y}.png?access_token=' + key,
  baseUrl +
    '/mapbox.blue-marble-topo-bathy-jul/{z}/{x}/{y}.png?access_token=' +
    key,
];

const source = new XYZ();

const map = new Map({
  target: 'map',
  layers: [
    new TileLayer({
      source: source,
    }),
  ],
  view: new View({
    center: [0, 0],
    zoom: 2,
  }),
});

function updateUrl(index) {
  source.setUrl(urls[index]);
}

const buttons = document.getElementsByClassName('switcher');
for (let i = 0, ii = buttons.length; i < ii; ++i) {
  const button = buttons[i];
  button.addEventListener('click', updateUrl.bind(null, Number(button.value)));
}

updateUrl(0);

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>Reusable Source</title>
    <link rel="stylesheet" href="node_modules/ol/ol.css">
    <style>
      .map {
        width: 100%;
        height: 400px;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <button class="switcher" value="0">January</button>
    <button class="switcher" value="1">January (with bathymetry)</button>
    <button class="switcher" value="2">July</button>
    <button class="switcher" value="3">July (with bathymetry)</button>
    <!-- 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>