原文链接及内容
有了ol/Layer和render函数，我们就可以使用交互式svg作为图层。将鼠标悬停在国家/地区上，可以看到通过css :hover伪类定义的交互性样式。
main.js代码如下：
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| import Layer from 'ol/layer/Layer.js';
import Map from 'ol/Map.js';
import View from 'ol/View.js';
import {composeCssTransform} from 'ol/transform.js';
const map = new Map({
target: 'map',
view: new View({
center: [0, 0],
extent: [-180, -90, 180, 90],
projection: 'EPSG:4326',
zoom: 2,
}),
});
const svgContainer = document.createElement('div');
const xhr = new XMLHttpRequest();
xhr.open('GET', 'data/world.svg');
xhr.addEventListener('load', function () {
const svg = xhr.responseXML.documentElement;
svgContainer.ownerDocument.importNode(svg);
svgContainer.appendChild(svg);
});
xhr.send();
const width = 2560;
const height = 1280;
const svgResolution = 360 / width;
svgContainer.style.width = width + 'px';
svgContainer.style.height = height + 'px';
svgContainer.style.transformOrigin = 'top left';
svgContainer.className = 'svg-layer';
map.addLayer(
new Layer({
render: function (frameState) {
const scale = svgResolution / frameState.viewState.resolution;
const center = frameState.viewState.center;
const size = frameState.size;
const cssTransform = composeCssTransform(
size[0] / 2,
size[1] / 2,
scale,
scale,
frameState.viewState.rotation,
-center[0] / svgResolution - width / 2,
center[1] / svgResolution - height / 2
);
svgContainer.style.transform = cssTransform;
svgContainer.style.opacity = this.getOpacity();
return svgContainer;
},
})
);
|
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>SVG Layer</title>
<link rel="stylesheet" href="node_modules/ol/ol.css">
<style>
.map {
width: 100%;
height: 400px;
}
#map {
background: black;
}
.svg-layer path:hover {
opacity: 0.4;
}
</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>
|
)
