Returns the geodesic area of a Polygon in the requested area units.

Namespace:  ESRI.ArcGISExplorer.Geometry

Assembly:  ESRI.ArcGISExplorer (in ESRI.ArcGISExplorer.dll) Version: 2.0.0.1500 (2.0.0.1500)

Syntax

C#
public static double Area(
	Polygon polygon,
	Unit areaUnit
)
Visual Basic (Declaration)
Public Shared Function Area ( _
	polygon As Polygon, _
	areaUnit As Unit _
) As Double

Parameters

polygon
Type: ESRI.ArcGISExplorer.Geometry..::.Polygon

The Polygon to measure.
areaUnit
Type: ESRI.ArcGISExplorer.Geometry..::.Unit

The area units of the returned measurement.

Return Value

The area, in areaUnit, of the polygon, measured geodesically.

Remarks

Geodesic measurements account for the curvature of the earths surface.

Examples

The code below shows how the Area property can be used to retrieve the area of a Polygon with linear units (a projected coordinate system). It also shows getting the area of a Polygon which has angular units (a geographic coordinate system) by using the GeodesicUtilities class Area method to return the area, specifying an area unit. Similar code can be applied to get the area of Envelopes.
CopyC#
    // Create a Polygon with a projected coordinate system.
    IEnumerable<ESRI.ArcGISExplorer.Geometry.Point> bngPoints = new ESRI.ArcGISExplorer.Geometry.Point[] { 
new ESRI.ArcGISExplorer.Geometry.Point(326872.482358681, 673940.581779784), 
new ESRI.ArcGISExplorer.Geometry.Point(326937.296501129, 673957.506541019), 
new ESRI.ArcGISExplorer.Geometry.Point(326953.836608697, 673895.000320552), 
new ESRI.ArcGISExplorer.Geometry.Point(326889.407119913, 673876.536944667), 
new ESRI.ArcGISExplorer.Geometry.Point(326887.099197928, 673887.307247264), 
new ESRI.ArcGISExplorer.Geometry.Point(326897.677173697, 673890.769130243), 
new ESRI.ArcGISExplorer.Geometry.Point(326884.791275943, 673934.23499432), 
new ESRI.ArcGISExplorer.Geometry.Point(326874.597953836, 673932.311725998), 
new ESRI.ArcGISExplorer.Geometry.Point(326872.482358681, 673940.581779784) };

    Polygon bngPolygon = new Polygon(bngPoints,
        CoordinateSystem.ProjectedCoordinateSystems.NationalGrids.Europe.BritishNationalGrid);

    // For geometries with projected coordinate systems, the Area can be retrieved directly.
    // British national grid uses Meters as its unit.
    double bngArea = bngPolygon.Area;

    // Project the polygon to create a geometry with a geographic coordinate system.
    Polygon wgs84Polygon = (Polygon)GeometryOperations.Project(bngPolygon,
        CoordinateSystem.GeographicCoordinateSystems.World.WGS1984, new GeographicTransformation(1195));

    // Use GeodesicUtilities to get Area for a geometry with a geographic coordinate system,
    // which has angular units 
    double wgs84Area = GeodesicUtilities.Area(wgs84Polygon, Unit.Area.SquareMeters);
CopyVB.NET
' Create a Polygon with a projected coordinate system.
Dim bngPoints As IEnumerable(Of ESRI.ArcGISExplorer.Geometry.Point) = New ESRI.ArcGISExplorer.Geometry.Point() { _
        New ESRI.ArcGISExplorer.Geometry.Point(326872.482358681, 673940.581779784), _
        New ESRI.ArcGISExplorer.Geometry.Point(326937.296501129, 673957.506541019), _
        New ESRI.ArcGISExplorer.Geometry.Point(326953.836608697, 673895.000320552), _
        New ESRI.ArcGISExplorer.Geometry.Point(326889.407119913, 673876.536944667), _
        New ESRI.ArcGISExplorer.Geometry.Point(326887.099197928, 673887.307247264), _
        New ESRI.ArcGISExplorer.Geometry.Point(326897.677173697, 673890.769130243), _
        New ESRI.ArcGISExplorer.Geometry.Point(326884.791275943, 673934.23499432), _
        New ESRI.ArcGISExplorer.Geometry.Point(326874.597953836, 673932.311725998), _
        New ESRI.ArcGISExplorer.Geometry.Point(326872.482358681, 673940.581779784)}

Dim bngPolygon As Polygon = New Polygon(bngPoints, _
    CoordinateSystem.ProjectedCoordinateSystems.NationalGrids.Europe.BritishNationalGrid)

' For geometries with projected coordinate systems, the Area can be retrieved directly.
' British national grid uses Meters as its unit.
Dim bngArea As Double = bngPolygon.Area

' Project the polygon to create a geometry with a geographic coordinate system.
Dim wgs84Polygon As Polygon = DirectCast(GeometryOperations.Project(bngPolygon, _
 CoordinateSystem.GeographicCoordinateSystems.World.WGS1984, New GeographicTransformation(1195)), Polygon)

' Use GeodesicUtilities to get Area for a geometry with a geographic coordinate system,
' which has angular units 
Dim wgs84Area As Double = GeodesicUtilities.Area(wgs84Polygon, Unit.Area.SquareMeters)

See Also