Centroid Method (IGeometryEngine)

In This Topic

Gets the centroid (center of gravity) of the geometry.

Syntax

C#
Visual Basic (Declaration)

MapPoint Centroid( 
   Geometry geometry
)

Function Centroid( _
   ByVal geometry As Geometry _
) As MapPoint

Parameters

geometry: The input geometry.

Return Value

Returns the centroid of the geometry.

Exceptions

Exception	Description
System.ArgumentNullException	Geometry is null or empty.
System.NotImplementedException	The method is not implemented for GeometryBag.

Remarks

If the geometry is a MapPoint, then the centroid returned is the same as the source; including Z and M-values (if any exist on the source geometry). The centroid of any other geometry type is a point with HasZ = false, HasM = false.

Example

Find the centroid of geometries

// simple polygon
List<Coordinate2D> list2D = new List<Coordinate2D>();
list2D.Add(new Coordinate2D(0, 0));
list2D.Add(new Coordinate2D(0, 2));
list2D.Add(new Coordinate2D(2, 2));
list2D.Add(new Coordinate2D(2, 0));

Polygon polygon = PolygonBuilderEx.CreatePolygon(list2D, SpatialReferences.WGS84);

// verify it is simple
bool isSimple = GeometryEngine.Instance.IsSimpleAsFeature(polygon);
// find the centroid
MapPoint centroid = GeometryEngine.Instance.Centroid(polygon);
// centroid.X = 1
// centroid.Y = 1

// map Point
MapPoint pt1 = MapPointBuilderEx.CreateMapPoint(1, 2, 3, 4, SpatialReferences.WGS84);
MapPoint pt2 = MapPointBuilderEx.CreateMapPoint(5, 2, double.NaN, 7);

// pt1.HasZ = true
// pt1.HasM = true
centroid = GeometryEngine.Instance.Centroid(pt1);
// centroid.HasZ = true
// centroid.HasM = true
// pt1.IsEqual(centroid) = true

// multipoint
List<MapPoint> list = new List<MapPoint>() { pt1, pt2 };
Multipoint multipoint = MultipointBuilderEx.CreateMultipoint(list);
// multipoint.HasZ = true
// multipoint.HasM = true

centroid = GeometryEngine.Instance.Centroid(multipoint);
// centroid.X = 3
// centroid.Y = 2
// centroid.HasZ = false
// centroid.HasM = false

Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.

Reference

IGeometryEngine Interface
IGeometryEngine Members

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