map 和 Layer wkid 不同时如何缩放到特征选择?

How to zoom to feature selection when map and Layer wkid are different?

我有一个使用 Esri ArcGis Js Api v3.11 的地图服务。

在该地图上,用户可以查询每个 FeatureLayer 并返回一个简单的网格。行单击事件附加了以下处理程序:

_grid.on('dgrid-select', function(event) {
    var data = event.rows[0].data;
    //get the current selected featureLayer
    //build a query against it, using the objectId
    //zoom to position: https://developers.arcgis.com/javascript/3/jssamples/fl_zoomgrid.html
    var layerUrl = dijit.byId("LayerSelectBox").get("value");
    var url = lang.replace(_baseUrl, { layer: layerUrl });
    var fl = new FeatureLayer(url, {
        mode: FeatureLayer.MODE_SELECTION,
        outFields: ["ObjectID"]
    });
    //clear selection
    fl.clearSelection();
    query.objectIds = [data.OBJECTID];
    fl.selectFeatures(query, FeatureLayer.SELECTION_NEW, function(features) {
        //zoom to the selected feature
        var geometryExtent = features[0].geometry.getExtent().expand(5.0);
        _map.setExtent(geometryExtent);
    });
});

虽然查询及其周围的一切工作正常,但缩放到结果让我很头疼。该地图的空间参考 Wkid 为 102100,返回的几何图形为 102362。

尝试将地图的范围设置为几何的范围或以点为中心会导致以下错误:

Map: Geometry (wkid: 102362) cannot be converted to spatial reference of the map (wkid: 102100)

.selectFeatures (https://developers.arcgis.com/javascript/3/jsapi/featurelayer-amd.html#selectfeatures) 的文档只提供了这一点有用的信息:

The input query. The query object has the following restrictions to avoid conflicts between layer and map properties.

  • outFields specified by the query object are overridden by the outFields specified in the FeatureLayer constructor.
  • The returnGeometry value specified by the query object is ignored and true is used.
  • The outSpatialReference set by the query object is ignored and the map's spatial reference is used.

老实说,这让我有点困惑。如何将结果 sr 转换/转换为地图 sr 并将地图居中?通过在地图上单击它来查询 FeatureLayer,会出现一个小对话框 Window,带有开箱即用的“缩放到”按钮,因此该功能可供使用。我似乎只是在做一些根本性的错误。

最后,GeometryService 拯救了我:

fl.selectFeatures(query, FeatureLayer.SELECTION_NEW, function(features) {

    var gmsvc = new GeometryService("url//to/Geometryservice");

    var fooExtent = graphicUtils.graphicsExtent(features);

    var projectParams = new ProjectParameters();  
    projectParams.geometries = [fooExtent];  
    projectParams.outSR = map.spatialReference;  
    gmsvc.project(projectParams).then(function(x) {
        map.setExtent(x[0]);
    })
});

我正在使用 graphicUtils 从一组几何图形计算范围。这不是绝对必要的,但由于我的结果可以是任何东西,从一个点到一个多边形,这是一个很好的接触并节省了一些开关语句。

接下来,我将使用我的几何服务将范围投影到地图的空间参考中,完成后,我将设置该范围。