使用 CLUSTERS 时如何让 GeoJSON 属性出现在 openlayers 3 弹出窗口中?

How to get GeoJSON properties to appear in openlayers 3 popup when using CLUSTERS?

我构建了一个相对简单的 openlayers 地图,我试图让我的 geoJSON 属性出现在我的点击弹出窗口中,但无论我尝试什么,它要么 returns 几何名称 object ObjectUndefined。我认为 openlayers 将集群数据存储为一组特征而不是多个单独的特征?这是我的点击功能的代码:

var
   container = document.getElementById('popup'),
   content_element = document.getElementById('popup-content'),
   closer = document.getElementById('popup-closer');

closer.onclick = function() {
overlay.setPosition(undefined);
closer.blur();
return false;
};

var overlay = new ol.Overlay({
element: container,
positioning: 'bottom-center',
stopEvent: false
});

map.addOverlay(overlay);
// display popup on click
map.on('click', function(evt) {
var feature = map.forEachFeatureAtPixel(evt.pixel,
  function(feature, layer) {
    return feature;
  });
if (feature) {
var geometry = feature.getGeometry();
    var coord = geometry.getCoordinates();

    var content =coord;
//------------------------------------------------------------------------------
    content += '<h5>' + feature.get('MMSI') + '</h5>';
//--------^^^^^^^ This does not work for clusters ^^^^^^------------------------
//------------------------------------------------------------------------------
    content_element.innerHTML = content;
    overlay.setPosition(coord);
} else {

}

我不需要实际聚类的属性,但我确实需要单个点的属性(一旦放大,聚类就会分离成单独的点)。非常感谢任何帮助!

试试这个方法:

map.on('click', function(evt) {
    var ft = map.forEachFeatureAtPixel(evt.pixel, function(f, l){return f;});
    if (ft) {
        var features = ft.get('features'); //this is from the official examples
        features.forEach(function(feature){

            //assumption there is a 'name' property
            console.info(feature.get('name'));

        });
    }
});