原文链接及内容
图层支持minZoom和maxZoom选项，用于根据视图的缩放级别控制可见性。如果设置了最小或最大缩放，则该图层将仅在大于minZoom且小于或等于maxZoom的缩放级别时可见。在图层被构建之后，还可以使用图层的setMinZoom和setMaxZoom方法来设置图层最小/大缩放级别。本例显示了缩放级别为14及以下的OSM图层和缩放级别高于14的USGS图层。
main.js代码如下：
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| import Map from 'ol/Map.js';
import OSM from 'ol/source/OSM.js';
import TileJSON from 'ol/source/TileJSON.js';
import TileLayer from 'ol/layer/Tile.js';
import View from 'ol/View.js';
import {fromLonLat} from 'ol/proj.js';
const key = 'Get your own API key at https://www.maptiler.com/cloud/';
const map = new Map({
target: 'map',
layers: [
new TileLayer({
maxZoom: 14,
source: new OSM(),
}),
new TileLayer({
minZoom: 14,
source: new TileJSON({
url: 'https://api.maptiler.com/maps/outdoor/tiles.json?key=' + key,
tileSize: 512,
}),
}),
],
view: new View({
center: fromLonLat([-112.18688965, 36.057944835]),
zoom: 15,
maxZoom: 18,
constrainOnlyCenter: true,
}),
});
|
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>Layer Zoom Limits</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>
<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>
|
)
