原文链接及内容

原文链接：https://openlayers.org/en/latest/examples/vector-labels-justify-text.html

运行界面

这个例子展示了如何在标签框中对齐文本。默认情况下，文本根据textAlign选项来对齐。但是，此选项也会根据textAlign设置来调整标签本身。要将标签放置与文本放置分离(在标签框中)，请使用justify选项。

main.js代码如下：

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import Collection from 'ol/Collection.js';
import Feature from 'ol/Feature.js';
import GeoJSON from 'ol/format/GeoJSON.js';
import Map from 'ol/Map.js';
import Point from 'ol/geom/Point.js';
import View from 'ol/View.js';
import {
  Circle as CircleStyle,
  Fill,
  Stroke,
  Style,
  Text,
} from 'ol/style.js';
import {OSM, Vector as VectorSource} from 'ol/source.js';
import {Tile as TileLayer, Vector as VectorLayer} from 'ol/layer.js';

const features = [
  {
    geometry: new Point([-8300000, 6095000]),
    textAlign: 'left',
  },
  {
    geometry: new Point([-8150000, 6095000]),
    textAlign: 'center',
  },
  {
    geometry: new Point([-8000000, 6095000]),
    textAlign: 'right',
  },
  {
    geometry: new Point([-8300000, 6025000]),
    textAlign: 'left',
    justify: 'center',
  },
  {
    geometry: new Point([-8150000, 6025000]),
    textAlign: 'center',
    justify: 'center',
  },
  {
    geometry: new Point([-8000000, 6025000]),
    textAlign: 'right',
    justify: 'center',
  },
  {
    geometry: new Point([-8300000, 5955000]),
    textAlign: 'left',
    justify: 'left',
  },
  {
    geometry: new Point([-8150000, 5955000]),
    textAlign: 'center',
    justify: 'left',
  },
  {
    geometry: new Point([-8000000, 5955000]),
    textAlign: 'right',
    justify: 'left',
  },
];

function createStyle({textAlign, justify}) {
  return new Style({
    image: new CircleStyle({
      radius: 10,
      fill: new Fill({color: 'rgba(255, 0, 0, 0.1)'}),
      stroke: new Stroke({color: 'red', width: 1}),
    }),
    text: new Text({
      font: '16px sans-serif',
      textAlign,
      justify,
      text:
        `Justify text inside box\ntextAlign: ${textAlign}` +
        (justify ? `\njustify: ${justify}` : ''),
      fill: new Fill({
        color: [255, 255, 255, 1],
      }),
      backgroundFill: new Fill({
        color: [168, 50, 153, 0.6],
      }),
      padding: [2, 2, 2, 2],
    }),
  });
}

const vectorPoints = new VectorLayer({
  source: new VectorSource({
    features: new Collection(
      features.map((featureOptions) => {
        const feature = new Feature({
          geometry: featureOptions.geometry,
        });
        feature.setStyle(createStyle(featureOptions));
        return feature;
      })
    ),
    format: new GeoJSON(),
  }),
});

const map = new Map({
  layers: [
    new TileLayer({
      source: new OSM(),
    }),
    vectorPoints,
  ],
  target: 'map',
  view: new View({
    center: [-8150000, 6025000],
    zoom: 8,
  }),
});

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>Vector Labels - Justify Text</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>