GeoJSON Class
Provides static methods for converting between the GeoJSON format and FeatureCollection.
NuGet/Assembly: Carmenta.Engine.5.16.2.nupkg (in the CECore assembly)
Syntax
public class GeoJSON : System.ObjectRemarks
The GeoJSON format describes a JSON structure to represent geographic features. This class enables the conversion between a GeoJSON representation and a FeatureCollection.
GeoJSON coordinates are specified in the coordinate reference system Crs.Wgs84LongLat. The Feature objects used as input to ToString and ToFile are expected to have WGS 84 as crs, otherwise an exception will be thrown.
While both GeoJSON and Carmenta Engine have a concept of "Feature", they are not the same: it's possible for one GeoJSON feature to translate into several Feature objects. Since support for multigeometries is limited in Carmenta Engine, a GeoJSON multigeometry will be translated into several corresponding Feature objects with the same Feature.Id.
Several Feature objects with the same id can be merged into one GeoJSON feature (this behavior can be controlled with parameters to ToString and ToFile). If they have the same Feature.GeometryType, the resulting GeoJSON will be a homogeneous multigeometry (MultiPoint, MultiLineString, MultiPolygon), otherwise the result is a GeometryCollection.
It's possible for a GeoJSON property value to be a JSON object, which does not trivially translate into a AttributeValue. In this case, the attribute value will be a string with the json object serialized, with a "json:" prefix to distringuish it from other string attribute values. Properties with null values are stored in the same way. Use this prefix when serializing Carmenta Engine features to add object or null properties to GeoJSON.
A GeoJSON feature may have an identifier, specified with the key "id". The resulting Feature object(s) will then have an attribute called "geojson_id". Use this attribute key when serializing Carmenta Engine features to add "id" in GeoJSON.
GeoJSON allows for some constructs which have no possible representation in Carmenta Engine features:
A GeoJSON feature's geometry can be null. These features are ignored.
Both features and geometries in GeoJSON can have a "bbox" key describing the bounding box for that object. This key is ignored.
Foreign members, as defined in the GeoJSON standard, are ignored.
Inheritance Hierarchy
System.Object (not available in C#)
GeoJSON
Platforms
Windows, Linux, Android
GeoJSON Members
The GeoJSON type has the following members.
Methods
| Name | Description |
|---|---|
 FromFile | Takes a UTF-8 encoded GeoJSON file as input and parses its content to features. |
| FromString | Takes a string as input and parses to features. |
| ToFile | Overloaded. Translates features into UTF-8 encoded GeoJSON, and saves the result to a specified file. |
| ToString | Overloaded. Translates features into a GeoJSON string. |