原文链接及内容

原文链接：https://openlayers.org/en/latest/examples/street-labels.html

运行界面

这个例子展示了如何使用带有placement: 'line'的文本样式来渲染沿着路径方向放置的文本。

main.js代码如下：

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import GeoJSON from 'ol/format/GeoJSON.js';
import Map from 'ol/Map.js';
import VectorSource from 'ol/source/Vector.js';
import View from 'ol/View.js';
import XYZ from 'ol/source/XYZ.js';
import {Fill, Style, Text} from 'ol/style.js';
import {Tile as TileLayer, Vector as VectorLayer} from 'ol/layer.js';
import {getCenter} from 'ol/extent.js';

const style = new Style({
  text: new Text({
    font: 'bold 11px "Open Sans", "Arial Unicode MS", "sans-serif"',
    placement: 'line',
    fill: new Fill({
      color: 'white',
    }),
  }),
});

const key = 'Get your own API key at https://www.maptiler.com/cloud/';
const attributions =
  '<a href="https://www.maptiler.com/copyright/" target="_blank">&copy; MapTiler</a> ' +
  '<a href="https://www.openstreetmap.org/copyright" target="_blank">&copy; OpenStreetMap contributors</a>';

const viewExtent = [1817379, 6139595, 1827851, 6143616];
const map = new Map({
  layers: [
    new TileLayer({
      source: new XYZ({
        attributions: attributions,
        url:
          'https://api.maptiler.com/tiles/satellite/{z}/{x}/{y}.jpg?key=' + key,
        maxZoom: 20,
      }),
    }),
    new VectorLayer({
      declutter: true,
      source: new VectorSource({
        format: new GeoJSON(),
        url: 'data/geojson/vienna-streets.geojson',
      }),
      style: function (feature) {
        style.getText().setText(feature.get('name'));
        return style;
      },
    }),
  ],
  target: 'map',
  view: new View({
    extent: viewExtent,
    center: getCenter(viewExtent),
    zoom: 17,
    minZoom: 14,
  }),
});

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>Street Labels</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>
    <!-- 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>