ArcGIS Pro 2.8 API Reference Guide
ToJson Method (Geometry)
Example 

ArcGIS.Core.Geometry Namespace > Geometry Class : ToJson Method
(Optional) Indicates if the spatial reference is to be skipped in the JSON output string. Default value is false.
Serializes this geometry instance into an ArcGIS JSON geometry representation.
Syntax
public string ToJson( 
   bool skipSR
)
Public Function ToJson( _
   Optional ByVal skipSR As Boolean _
) As String

Parameters

skipSR
(Optional) Indicates if the spatial reference is to be skipped in the JSON output string. Default value is false.

Return Value

Geometry represented as a JSON string.
Remarks
Note that if the geometry contains ID information, this property will not be preserved in the JSON string. ID is not part of the JSON specification.
Example
// MapPoint
string inputString = "{\"x\":1,\"y\":2,\"spatialReference\":{\"wkid\":4326,\"latestWkid\":4326}}";
Geometry geometry = GeometryEngine.Instance.ImportFromJSON(JSONImportFlags.jsonImportDefaults, inputString);

MapPoint importPoint = geometry as MapPoint;
// importPoint = 1, 2
// importPoint.SpatialReference.WKid = 4326

// use the MapPointBuilder convenience method
MapPoint importPoint2 = MapPointBuilder.FromJson(inputString);
// importPoint2 = 1, 2
// impointPoint2.SpatialReference.Wkid = 4326

string outputString = GeometryEngine.Instance.ExportToJSON(JSONExportFlags.jsonExportDefaults, importPoint);
// outputString =  "{\"x\":1,\"y\":2,\"spatialReference\":{\"wkid\":4326,\"latestWkid\":4326}}"

string outputString2 = importPoint.ToJson();

inputString = "{\"spatialReference\":{\"wkid\":4326},\"z\":3,\"m\":4,\"x\":1,\"y\":2}";
importPoint = GeometryEngine.Instance.ImportFromJSON(JSONImportFlags.jsonImportDefaults, inputString) as MapPoint;
// importPoint.HasM = true
// importPoint.HasZ = true
// importPoint.X = 1
// importPoint.Y = 2
// importPoint.M = 4
// importPoint.Z = 3

importPoint2 = MapPointBuilder.FromJson(inputString);

// export to json - skip spatial reference
outputString = GeometryEngine.Instance.ExportToJSON(JSONExportFlags.jsonExportSkipCRS, importPoint);
// outputString = "{\"x\":1,\"y\":2,\"z\":3,\"m\":4}"

// export from mappoint, skipping the sr - same as GeometryEngine.Instance.ExportToJSON w JSONExportFlags.jsonExportSkipCRS
outputString2 = importPoint.ToJson(true);

//
// Multipoint
//
List<Coordinate2D> coords = new List<Coordinate2D>()
{
  new Coordinate2D(100, 200),
  new Coordinate2D(201, 300),
  new Coordinate2D(301, 400),
  new Coordinate2D(401, 500)
};

Multipoint multipoint = MultipointBuilder.CreateMultipoint(coords, SpatialReferences.WebMercator);

inputString = "{\"points\":[[100,200],[201,300],[301,400],[401,500]],\"spatialReference\":{\"wkid\":3857}}";
Multipoint importMultipoint = GeometryEngine.Instance.ImportFromJSON(JSONImportFlags.jsonImportDefaults, inputString) as Multipoint;
// importMultipoint.IsEqual(multipoint) = true

ReadOnlyPointCollection points = importMultipoint.Points;
// points.Count = 4
// points[0] = 100, 200
// points[1] = 201, 300
// points[2] = 301, 400
// points[3] = 401, 500

// use the Multipointbuilder convenience method
Multipoint importMultipoint2 = MultipointBuilder.FromJson(inputString);
// importMultipoint2.IsEqual(multipoint) = true

// export to json
outputString = GeometryEngine.Instance.ExportToJSON(JSONExportFlags.jsonExportDefaults, multipoint);
// outputString = inputString

// or use the multipoint itself
outputString2 = multipoint.ToJson();

//
// Polyline
//
Polyline polyline = PolylineBuilder.CreatePolyline(coords, SpatialReferences.WebMercator);

// export without the spatial reference
outputString = GeometryEngine.Instance.ExportToJSON(JSONExportFlags.jsonExportSkipCRS, polyline);
// import
geometry = GeometryEngine.Instance.ImportFromJSON(JSONImportFlags.jsonImportDefaults, outputString);
Polyline importPolyline = geometry as Polyline;
// importPolyline.SpatialReference = null


points = importPolyline.Points;
// points.Count = 4
// points[0] = 100, 200
// points[1] = 201, 300
// points[2] = 301, 400
// points[3] = 401, 500

// use the polylineBuilder convenience method 
Polyline importPolyline2 = PolylineBuilder.FromJson(outputString);
// importPolyline2 = importPolyline

outputString2 = importPolyline2.ToJson();
// outputString2 = outputString

//
// Polygon
//
Polygon polygon = PolygonBuilder.CreatePolygon(coords, SpatialReferences.WebMercator);

// export without the spatial reference
outputString = GeometryEngine.Instance.ExportToJSON(JSONExportFlags.jsonExportSkipCRS, polygon);
// import
geometry = GeometryEngine.Instance.ImportFromJSON(JSONImportFlags.jsonImportDefaults, outputString);

Polygon importPolygon = geometry as Polygon;
// importPolygon.SpatialReference = null
points = importPolygon.Points;
// points.Count = 5

// polygonBuilder convenience method
Polygon importPolyon2 = PolygonBuilder.FromJson(outputString);
// importPolygon2 = importPolygon

// export from the polygon
outputString2 = importPolyon2.ToJson(true);

// Empty polygon
polygon = PolygonBuilder.CreatePolygon(SpatialReferences.WebMercator);
outputString = GeometryEngine.Instance.ExportToJSON(JSONExportFlags.jsonExportDefaults, polygon);
importPolygon = GeometryEngine.Instance.ImportFromJSON(JSONImportFlags.jsonImportDefaults, outputString) as Polygon;

// importPolygon.IsEmpty = true
// importPolygon.SpatialReference.Wkid = 3857
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

Geometry Class
Geometry Members