原文链接及内容
视图的minZoom选项限制了可以缩放的范围。可以通过调用view.setMinZoom(newMinZoom)来更新此属性。在本例中，设置了最小缩放级别，以便一次只能看到一个世界，可以调整浏览器窗口的大小以更改阈值。
main.js代码如下：
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
| import Map from 'ol/Map.js';
import OSM from 'ol/source/OSM.js';
import TileLayer from 'ol/layer/Tile.js';
import View from 'ol/View.js';
const viewport = document.getElementById('map');
function getMinZoom() {
const width = viewport.clientWidth;
return Math.ceil(Math.LOG2E * Math.log(width / 256));
}
const initialZoom = getMinZoom();
const view = new View({
center: [0, 0],
minZoom: initialZoom,
zoom: initialZoom,
});
const map = new Map({
layers: [
new TileLayer({
source: new OSM(),
}),
],
target: 'map',
view: view,
});
window.addEventListener('resize', function () {
const minZoom = getMinZoom();
if (minZoom !== view.getMinZoom()) {
view.setMinZoom(minZoom);
}
});
|
界面布局文件index.html代码如下：
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
| <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>View Min-Zoom</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>
|
)
