将EsriGeometry转为GeoJson

        public static string ConvertEsriGeometryToGeoJson(IGeometry esriGeometry)
        {
            byte[] b = ConvertGeometryToWKB(esriGeometry);
            WKBReader reader = new WKBReader();
            NetTopologySuite.Geometries.Geometry geometry = reader.Read(b);
            GeoJsonWriter geoJsonWriter = new GeoJsonWriter();
            return geoJsonWriter.Write(geometry);
        }

        public static byte[] ConvertGeometryToWKB(IGeometry geometry)
        {
            IWkb wkb = geometry as IWkb;
            ITopologicalOperator oper = geometry as ITopologicalOperator;
            oper.Simplify();
            IGeometryFactory3 factory = new GeometryEnvironment() as IGeometryFactory3;
            byte[] b = factory.CreateWkbVariantFromGeometry(geometry) as byte[];
            return b;
        }