OpenLayers示例代码：单图像WMS与Proj4js
OpenLayers示例代码：单图像WMS与Proj4js
<!DOCTYPE html>
<html>
<head>
<title>Single Image WMS with Proj4js</title>
<link rel="stylesheet" href="https://openlayers.org/en/v4.0.1/css/ol.css" type="text/css">
<!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
<script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"></script>
<script src="https://openlayers.org/en/v4.0.1/build/ol.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/proj4js/2.3.15/proj4.js"></script>
<script src="https://epsg.io/21781-1753.js"></script>
</head>
<body>
<div id="map" class="map"></div>
<script>
// Transparent Proj4js support:
//
// EPSG:21781 is known to Proj4js because its definition was loaded in the html.
// Now when we create an ol.proj.Projection instance with the 'EPSG:21781' code,
// OpenLayers will pick up parameters like units and transform functions from
// Proj4js.
//
// Note that we are setting the projection's extent here, which is used to
// determine the view resolution for zoom level 0. Recommended values for a
// projection's validity extent can be found at https://epsg.io/.
//
// If you use Proj4js only to transform coordinates, you don't even need to
// create an ol.proj.Projection instance. ol.proj.get() will take care of it
// internally.
var projection = new ol.proj.Projection({
code: 'EPSG:21781',
extent: [485869.5728, 76443.1884, 837076.5648, 299941.7864]
});
var extent = [420000, 30000, 900000, 350000];
var layers = [
new ol.layer.Image({
extent: extent,
source: new ol.source.ImageWMS({
url: 'https://wms.geo.admin.ch/',
crossOrigin: 'anonymous',
attributions: '© <a href="http://www.geo.admin.ch/internet/geoportal/' +
'en/home.html">Pixelmap 1:1000000 / geo.admin.ch</a>',
params: {
'LAYERS': 'ch.swisstopo.pixelkarte-farbe-pk1000.noscale',
'FORMAT': 'image/jpeg'
},
serverType: /** @type {ol.source.WMSServerType} */ ('mapserver')
})
}),
new ol.layer.Image({
extent: extent,
source: new ol.source.ImageWMS({
url: 'https://wms.geo.admin.ch/',
crossOrigin: 'anonymous',
attributions: '© <a href="http://www.geo.admin.ch/internet/geoportal/' +
'en/home.html">National parks / geo.admin.ch</a>',
params: {'LAYERS': 'ch.bafu.schutzgebiete-paerke_nationaler_bedeutung'},
serverType: /** @type {ol.source.WMSServerType} */ ('mapserver')
})
})
];
var map = new ol.Map({
controls: ol.control.defaults().extend([
new ol.control.ScaleLine()
]),
layers: layers,
target: 'map',
view: new ol.View({
projection: projection,
center: ol.proj.fromLonLat([8.23, 46.86], projection),
extent: extent,
zoom: 2
})
});
</script>
</body>
</html>
说明：
OpenLayers示例代码：单图像WMS与Proj4js
