javascript - 将 map 标记添加到 Open Layers 6

Question

我的问题很简单:如何在特定的经度和纬度添加标记？

通过开放层进行工作 example page我创建了一张带有标记的新 map 。

我使用new ol.Feature添加了标记，但似乎无论我设置什么，标记位置的坐标都不会改变。

请问有人可以就 map 标记未显示在正确位置的原因提供建议吗？

const iconFeature = new ol.Feature({
  geometry: new ol.geom.Point([53, -2]), //This marker will not move.
  name: 'Somewhere',
});

const map = new ol.Map({
  target: 'map',
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM(),
    }),
    new ol.layer.Vector({
      source: new ol.source.Vector({
        features: [iconFeature]
      }),
      style: new ol.style.Style({
        image: new ol.style.Icon({
          anchor: [0.5, 46],
          anchorXUnits: 'fraction',
          anchorYUnits: 'pixels',
          src: 'https://openlayers.org/en/latest/examples/data/icon.png'
        })
      })
    })
  ],
  view: new ol.View({
    center: ol.proj.fromLonLat([53,-2]),
    zoom: 6
  })
});

.map {
  width: 100%;
  height: 400px;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v6.1.1/build/ol.js"></script>

<div id="map" class="map">
  <div id="popup"></div>
</div>

Answer 1

您可以使用 ol.proj.fromLonLat 将 EPSG:4326 转换为 EPSG:3857，以获取功能并将 map 居中。一般来说，您必须这样做，因为默认投影是 EPSG:3857。

对于图标:

const iconFeature = new ol.Feature({
  geometry: new ol.geom.Point(ol.proj.fromLonLat([-2, 53])),
  name: 'Somewhere near Nottingham',
});

将 View / map 置于同一位置中心:

view: new ol.View({
  center: ol.proj.fromLonLat([-2, 53]),
  zoom: 6
})

工作代码片段:

const iconFeature = new ol.Feature({
  geometry: new ol.geom.Point(ol.proj.fromLonLat([-2, 53])),
  name: 'Somewhere near Nottingham',
});

const map = new ol.Map({
  target: 'map',
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM(),
    }),
    new ol.layer.Vector({
      source: new ol.source.Vector({
        features: [iconFeature]
      }),
      style: new ol.style.Style({
        image: new ol.style.Icon({
          anchor: [0.5, 46],
          anchorXUnits: 'fraction',
          anchorYUnits: 'pixels',
          src: 'https://openlayers.org/en/latest/examples/data/icon.png'
        })
      })
    })
  ],
  view: new ol.View({
    center: ol.proj.fromLonLat([-2, 53]),
    zoom: 6
  })
});

html, body {
  width: 100%;
  height: 100%;
  padding: 0px;
  margin: 0px;
}
.map {
  width: 100%;
  height: 100%;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@main/dist/en/v6.14.1/css/ol.css" type="text/css">
<script src="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@main/dist/en/v6.14.1/build/ol.js"></script>

<div id="map" class="map">
  <div id="popup"></div>
</div>