原文链接及内容

运行界面

此示例使用基于切片的加载策略从Geoserver WFS加载新要素。调用ol/proj模块中的useGeography()函数可以使地图视图使用地理坐标(即使视图投影不是地理坐标)。

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 {Stroke, Style} from 'ol/style.js';
import {Tile as TileLayer, Vector as VectorLayer} from 'ol/layer.js';
import {createXYZ} from 'ol/tilegrid.js';
import {tile} from 'ol/loadingstrategy.js';
import {useGeographic} from 'ol/proj.js';

useGeographic();

const vectorSource = new VectorSource({
format: new GeoJSON(),
url: function (extent) {
return (
'https://ahocevar.com/geoserver/wfs?service=WFS&' +
'version=1.1.0&request=GetFeature&typename=osm:water_areas&' +
'outputFormat=application/json&srsname=EPSG:4326&' +
'bbox=' +
extent.join(',') +
',EPSG:4326'
);
},
strategy: tile(createXYZ({tileSize: 512})),
});

const vector = new VectorLayer({
source: vectorSource,
style: new Style({
stroke: new Stroke({
color: 'rgba(0, 0, 255, 1.0)',
width: 2,
}),
}),
});

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 raster = new TileLayer({
source: new XYZ({
attributions: attributions,
url: 'https://api.maptiler.com/tiles/satellite/{z}/{x}/{y}.jpg?key=' + key,
maxZoom: 20,
}),
});

const map = new Map({
layers: [raster, vector],
target: document.getElementById('map'),
view: new View({
center: [-80.0298, 43.4578],
maxZoom: 19,
zoom: 12,
}),
});

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>WFS with geographic coordinates</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>