Area Method (IGeometryEngine)

In This Topic

Gets the area of the geometry. This is a planar measurement using 2D Cartesian mathematics to compute the area.

Syntax

C#
Visual Basic (Declaration)

double Area( 
   Geometry geometry
)

Function Area( _
   ByVal geometry As Geometry _
) As Double

Parameters

geometry: The geometry of which the area will be calculated.

Return Value

The computed area in the same units as the geometry's spatial reference unit. If the geometry is empty, then zero is returned.

Exceptions

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

Example

Build a donut polygon

List<Coordinate2D> outerCoordinates = new List<Coordinate2D>();
outerCoordinates.Add(new Coordinate2D(10.0, 10.0));
outerCoordinates.Add(new Coordinate2D(10.0, 20.0));
outerCoordinates.Add(new Coordinate2D(20.0, 20.0));
outerCoordinates.Add(new Coordinate2D(20.0, 10.0));

// define the inner polygon as anti-clockwise
List<Coordinate2D> innerCoordinates = new List<Coordinate2D>();
innerCoordinates.Add(new Coordinate2D(13.0, 13.0));
innerCoordinates.Add(new Coordinate2D(17.0, 13.0));
innerCoordinates.Add(new Coordinate2D(17.0, 17.0));
innerCoordinates.Add(new Coordinate2D(13.0, 17.0));

PolygonBuilderEx pbEx = new PolygonBuilderEx(outerCoordinates);
Polygon donutEx = pbEx.ToGeometry() as Polygon;
double areaEx = donutEx.Area;       // area = 100

pbEx.AddPart(innerCoordinates);
donutEx = pbEx.ToGeometry() as Polygon;

areaEx = donutEx.Area;    // area = 84.0

areaEx = GeometryEngine.Instance.Area(donutEx);    // area = 84.0

Determine area of a polygon

var g1 = PolygonBuilderEx.FromJson("{\"rings\": [ [ [0, 0], [10, 0], [10, 10], [0, 10] ] ] }");
double d = GeometryEngine.Instance.Area(g1);
// d = -100.0         //negative due to wrong ring orientation
d = GeometryEngine.Instance.Area(GeometryEngine.Instance.SimplifyAsFeature(g1));
// d = 100.0        // feature has been simplifed; ring orientation is correct

Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.

Reference

IGeometryEngine Interface
IGeometryEngine Members

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