OpenLayers 转换 EPSG

Question

我正在准备一个在 OpenStreetMap 上可视化多多边形数据的项目。我正在定义为

MULTIPOLYGON(((497700.486018679 520452.398175831,497716.241129864 520362.650580387,497790.667185966 520394.23154406,497700.486018679 520452.398175831)))

的示例区域上测试该解决方案。该区域位于 EPSG:2180 中，并在此处正确显示：https://wktmap.com/?d98dcd08。根据可用的在线资源，我开发了以下代码；但是，它以 EPSG:3857 的形式在地图上显示数据。我需要帮助来理解正确的代码应该如何可视化 EPSG:2180 中的多边形区域。

<!DOCTYPE html>
<html>
<head>
<title>WKT example</title>
<script src="https://code.jquery.com/jquery-1.11.2.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/openlayers/4.6.5/ol.css" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/openlayers/4.6.5/ol.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/proj4js/2.9.1/proj4.js" integrity="sha512-b6xGAphpoiHdO8C81RQ2fF+kGmPrtMnBoZhbI4Z3OYGv0paVMl+WYQhuF5qg7OmjDagVEJvuvUKvdg52hT8qRw==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
</head>
<body>
<div class="container-fluid">
    <div class="row-fluid">
        <div class="span12">
            <div id="map" class="map"></div>
        </div>
    </div>
</div>
<script>
    var raster = new ol.layer.Tile({
        source: new ol.source.OSM()
    });

    var format = new ol.format.WKT();
    var feature = format.readFeature(
        'MULTIPOLYGON(((497700.486018679 520452.398175831,497716.241129864 520362.650580387,497790.667185966 520394.23154406,497700.486018679 520452.398175831)))', {
            dataProjection: 'EPSG:2180',
            featureProjection: 'EPSG:2180'
        });
    var vector = new ol.layer.Vector({
        source: new ol.source.Vector({
            features: [feature]
        })
    });
    var map = new ol.Map({
        layers: [raster, vector],
        target: 'map',
        view: new ol.View({
            center: [497700.486018679, 520452.398175831],
            zoom: 14
        })
    });
</script>
</body>
</html>

Answer 1

添加投影定义并更正后

featureProjection

OpenLayers 4.6.5 似乎与最新版本的 proj4.js 兼容。视图中心也需要从 EPSG:2180 转换为视图投影。

<!DOCTYPE html>
<html>
<head>
<title>WKT example</title>
<script src="https://code.jquery.com/jquery-1.11.2.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/openlayers/4.6.5/ol.css" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/openlayers/4.6.5/ol.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/proj4js/2.9.1/proj4.js" integrity="sha512-b6xGAphpoiHdO8C81RQ2fF+kGmPrtMnBoZhbI4Z3OYGv0paVMl+WYQhuF5qg7OmjDagVEJvuvUKvdg52hT8qRw==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
<script src="https://epsg.io/2180.js"></script>
</head>
<body>
<div class="container-fluid">
    <div class="row-fluid">
        <div class="span12">
            <div id="map" class="map"></div>
        </div>
    </div>
</div>
<script>
    var raster = new ol.layer.Tile({
        source: new ol.source.OSM()
    });

    var format = new ol.format.WKT();
    var feature = format.readFeature(
        'MULTIPOLYGON(((497700.486018679 520452.398175831,497716.241129864 520362.650580387,497790.667185966 520394.23154406,497700.486018679 520452.398175831)))', {
            dataProjection: 'EPSG:2180',
            featureProjection: 'EPSG:3857'
        });
    var vector = new ol.layer.Vector({
        source: new ol.source.Vector({
            features: [feature]
        })
    });
    var map = new ol.Map({
        layers: [raster, vector],
        target: 'map',
        view: new ol.View({
            center: ol.proj.transform([497700.486018679, 520452.398175831], 'EPSG:2180', 'EPSG:3857'),
            zoom: 14
        })
    });
</script>
</body>
</html>

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