GeometryBuilder class final

Geometry builders allow you to create and modify geometries incrementally.

This is the base class for a range of geometry builders, such as a PointBuilder, PolylineBuilder and PolygonBuilder. Each GeometryType has a corresponding type of builder. You can create and modify polygons with PolygonBuilder, envelopes with EnvelopeBuilder, and so on. Use a geometry builder in editing workflows where you need to build up or edit geometry one vertex at a time, for example, when you need to add or edit a vertex from a custom streaming GIS data source. You can either create an empty geometry builder and build up the shape of a Geometry, or you can create a geometry builder with an existing Geometry and modify it.

When you construct the builder, you can explicitly set its SpatialReference or you can construct the builder with a geometry and the builder will adopt the Geometry.spatialReference. Once set, the SpatialReference cannot be changed. The SpatialReference of any geometry or coordinates added to the builder must be compatible with the SpatialReference of the builder, as they will not be reprojected. The SpatialReference of a geometry added to the builder can be null, in which case the object is assumed to have the same SpatialReference as the builder it is added to.

There are other ways to create and edit geometries. If you know all the geometry coordinates up front, then you can use geometry constructors, such as Polygon, to create the geometry. If you are going to create a new geometry as a result of a topological operation, such as the buffer operation, then explore the GeometryEngine. If you want your app users to interactively create or edit geometries in the user interface then use the GeometryEditor.