我的Django模型中有一个空间字段。我想在地图上显示此字段。怎么做?在带有Django内置OSMWidget和OpenLayers的Django Admin中,它可以正常工作。
如果我尝试访问模板中的空间字段,则其格式如下:
SRID=4326;GEOMETRYCOLLECTION (POLYGON ((54.57842969715517 23.34800720214843, 54.53144199643833 23.29547882080078, 54.52964902093564 23.38096618652343, 54.57444978782305 23.40499877929688, 54.57842969715517 23.34800720214843)))
格式为WKT(众所周知的文本),使用OL,您只需使用ol.format.WKT
即可读取所有或单个功能(OL API - WKT format)。
我根据OL示例OL Examples - WKT为您提供了此示例。我想显示一种特殊性或GEOMETRYCOLLECTION
,它可以包含不同类型的几何图形,并非总是需要巫婆。
<!doctype html>
<html lang="en">
<head>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v6.3.1/css/ol.css" type="text/css">
<style>
.map {
height: 400px;
width: 100%;
}
</style>
<script src="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v6.3.1/build/ol.js"></script>
<title>WKT Geometry</title>
</head>
<body>
<h2>My Map</h2>
<div id="map" class="map"></div>
<script type="text/javascript">
const wkt = 'GEOMETRYCOLLECTION('+
'MULTIPOINT(-2 3 , -2 2),'+
'LINESTRING(5 5 ,10 10),'+
'POLYGON((-7 4.2,-7.1 5,-7.1 4.3,-7 4.2)))';
const format = new ol.format.WKT();
const features = format.readFeatures(wkt, {
dataProjection: 'EPSG:4326',
featureProjection: 'EPSG:3857'
});
const vector = new ol.layer.Vector({
source: new ol.source.Vector({
features
}),
style: new ol.style.Style({
fill: new ol.style.Fill({
color: 'rgba(255, 255, 255, 0.2)'
}),
stroke: new ol.style.Stroke({
color: '#ff3333',
width: 2
}),
image: new ol.style.Circle({
radius: 7,
fill: new ol.style.Fill({
color: '#ff3333'
})
})
})
});
const map = new ol.Map({
target: 'map',
layers: [
new ol.layer.Tile({
source: new ol.source.OSM()
}),
vector
],
view: new ol.View({
center: ol.proj.fromLonLat([0, 5]),
zoom: 5
})
});
</script>
</body>
</html>