原文链接及内容

运行界面

WMS可以用作图像图层,就像上面这个例子所示;也可用作切片图层,如Tiled WMS示例所示。切片可以缓存,因此浏览器不会重新获取已经查看过的区域的数据。但对于不知道切片的WMS服务器来说,可能存在重复标签的问题(这句话没翻译明白,但感觉可以参考自定义Canvas切片这里例子来理解一下这句话),在这种情况下,单一图像WMS将产生更好的制图效果。

main.js代码如下:

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import ImageWMS from 'ol/source/ImageWMS.js';
import Map from 'ol/Map.js';
import OSM from 'ol/source/OSM.js';
import View from 'ol/View.js';
import {Image as ImageLayer, Tile as TileLayer} from 'ol/layer.js';

const layers = [
new TileLayer({
source: new OSM(),
}),
new ImageLayer({
extent: [-13884991, 2870341, -7455066, 6338219],
source: new ImageWMS({
url: 'https://ahocevar.com/geoserver/wms',
params: {'LAYERS': 'topp:states'},
ratio: 1,
serverType: 'geoserver',
}),
}),
];
const map = new Map({
layers: layers,
target: 'map',
view: new View({
center: [-10997148, 4569099],
zoom: 4,
}),
});

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>Single Image WMS</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>