富文本标签

富文本标签.

在本地图中使用不同的字体来创建清晰的北京：字母排序键前的州名为黑体，人口密度在第二行，小字体、斜体。

main.js

import GeoJSON from 'ol/format/GeoJSON.js';
import Map from 'ol/Map.js';
import VectorLayer from 'ol/layer/Vector.js';
import VectorSource from 'ol/source/Vector.js';
import View from 'ol/View.js';
import {Fill, Stroke, Style, Text} from 'ol/style.js';

const map = new Map({
  target: 'map',
  view: new View({
    center: [0, 0],
    zoom: 2,
    extent: [-13882269, 2890586, -7456136, 6340207],
    showFullExtent: true,
  }),
});

const labelStyle = new Style({
  text: new Text({
    font: '13px Calibri,sans-serif',
    fill: new Fill({
      color: '#000',
    }),
    stroke: new Stroke({
      color: '#fff',
      width: 4,
    }),
  }),
});
const countryStyle = new Style({
  fill: new Fill({
    color: 'rgba(255, 255, 255, 0.6)',
  }),
  stroke: new Stroke({
    color: '#319FD3',
    width: 1,
  }),
});
const style = [countryStyle, labelStyle];

const vectorLayer = new VectorLayer({
  background: 'white',
  source: new VectorSource({
    url: 'https://openlayers.org/data/vector/us-states.json',
    format: new GeoJSON(),
  }),
  style: function (feature) {
    labelStyle
      .getText()
      .setText([
        feature.getId(),
        'bold 13px Calibri,sans-serif',
        ` ${feature.get('name')}`,
        '',
        '\n',
        '',
        `${feature.get('density')} people/mi²`,
        'italic 11px Calibri,sans-serif',
      ]);
    return style;
  },
});

map.addLayer(vectorLayer);

index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Rich Text 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="./resources/elm-pep.js"></script>
    <script type="module" src="main.js"></script>
  </body>
</html>

package.json

{
  "name": "rich-text-labels",
  "dependencies": {
    "ol": "7.3.0"
  },
  "devDependencies": {
    "vite": "^3.2.3"
  },
  "scripts": {
    "start": "vite",
    "build": "vite build"
  }
}