OpenLayers => feature为null

时间:2011-10-09 09:42:47

标签: javascript jquery json openlayers geojson

这是我的GeoJSON结果。 PasteBin 但是当我加载它时,我在firebug中获得的结果是null。为什么,我的结果有错误吗? JSON中的坐标是用投影WGS84编写的,在代码中我也将外部投影设置为WGS84。那么为什么我得到返回“功能为空”? 我用来管理我的地图的代码是:

$(document).ready(function() {
var wgs84 = new OpenLayers.Projection('EPSG:4326');
var layer = null;
var map = new OpenLayers.Map('map',{projection: wgs84});
  layer = new OpenLayers.Layer.OSM( "Simple OSM Map");
    var baseProjection = layer.projection; 
  map.addLayer(layer);
  map.setCenter(new OpenLayers.LonLat(10,10), 4);
  map.events.register("moveend", null, function(){

      if(map.zoom == 10)
      {
        var bounds = map.getExtent();
        console.log(bounds);
        var ne = new OpenLayers.LonLat(bounds.right,bounds.top).transform(map.getProjectionObject(),wgs84);
        var sw = new OpenLayers.LonLat(bounds.left,bounds.bottom).transform(map.getProjectionObject(),wgs84);
        var vectorLayer = new OpenLayers.Layer.Vector();
        map.addLayer(vectorLayer);
        $.getJSON('ajax.php?a=markers&type=json&sw=('+sw.lon+','+sw.lat+')&ne=('+ne.lon+','+ne.lat+')',function(data){
        //$.getJSON('test.json',function(data){
            var geojson_format = new OpenLayers.Format.GeoJSON({
                'externalProjection': wgs84,
                'internalProjection': baseProjection
                });
            vectorLayer.addFeatures(geojson_format.read(data));
        });
        }
    });
});

1 个答案:

答案 0 :(得分:2)

您的示例OpenLayer代码工作正常,问题出在您的GeoJSON中:您错误拼写坐标“coordninates”