ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Core.Geometry Namespace / IGeometryEngine Interface / Project Method
The geometry to be projected. If the input geometry is empty, then an empty geometry with the output spatial reference is returned.
The spatial reference to which the geometry will be projected.
Example Version

Project Method (IGeometryEngine)
Projects the given geometry to a new spatial reference. Same as GeometryEngine.ProjectEx(geometry, ProjectionTransformation.Create(geometry.SpatialReference, outputSpatialReference)); or, if both spatial references have vertical coordinate systems same as GeometryEngine.ProjectEx(geometry, ProjectionTransformation.CreateWithVertical(geometry.SpatialReference, outputSpatialReference));
Syntax

Parameters

geometry
The geometry to be projected. If the input geometry is empty, then an empty geometry with the output spatial reference is returned.
outputSpatialReference
The spatial reference to which the geometry will be projected.

Return Value

The projected geometry.
Exceptions
ExceptionDescription
Geometry is null.
The method is not implemented for GeometryBag.
geometry.SpatialReference or output spatial reference is null.
geometry.SpatialReference or output spatial reference is unknown coordinate system.
Example
Project from WGS84 to WebMercator
MapPoint pt = MapPointBuilderEx.CreateMapPoint(1.0, 3.0, SpatialReferences.WGS84);
Geometry result = GeometryEngine.Instance.Project(pt, SpatialReferences.WebMercator);
MapPoint projectedPt = result as MapPoint;
Project from WGS84
// create the polygon
List<MapPoint> pts = new List<MapPoint>();
pts.Add(MapPointBuilderEx.CreateMapPoint(1.0, 1.0, SpatialReferences.WGS84));
pts.Add(MapPointBuilderEx.CreateMapPoint(1.0, 2.0, SpatialReferences.WGS84));
pts.Add(MapPointBuilderEx.CreateMapPoint(2.0, 2.0, SpatialReferences.WGS84));
pts.Add(MapPointBuilderEx.CreateMapPoint(2.0, 1.0, SpatialReferences.WGS84));

Polygon polygon = PolygonBuilderEx.CreatePolygon(pts);
// ensure it is simple
bool isSimple = GeometryEngine.Instance.IsSimpleAsFeature(polygon);

// create the spatial reference to project to
SpatialReference northPole = SpatialReferenceBuilder.CreateSpatialReference(102018);   // north pole stereographic 

// project
Geometry geometry = GeometryEngine.Instance.Project(polygon, northPole);
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also