ShapePreservingLength(Geometry,LinearUnit) Method

Calculates the length of the geometry on the surface of the Earth ellipsoid. This method preserves the shape of the geometry in its coordinate system.

Syntax

C#
Visual Basic (Declaration)

double ShapePreservingLength( 
   Geometry geometry,
   LinearUnit lengthUnit
)

Overloads Function ShapePreservingLength( _
   ByVal geometry As Geometry, _
   ByVal lengthUnit As LinearUnit _
) As Double

Parameters

geometry: The input geometry. Cannot be null and its spatial reference cannot be null.
lengthUnit: The unit of the output length. If null, then the length is in meters.

Return Value

Shape preserving length of the geometry in . If is null, then the shape preserving length is in meters.

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 or Multipatch.
ProjectionEngineException	Geometry is missing a spatial reference.
System.NotImplementedException	Spatial reference of geometryis an image coordinate system.

Remarks

This method preserves the shape of the geometry in its coordinate system. In other words, the length will be calculated for the geometry you see in the map. For example, if you have a polyline with only two vertices that represents the equator, the length returned will be the length of the equator.

Example

// pt
MapPoint pt = MapPointBuilder.CreateMapPoint(1.0, 3.0, SpatialReferences.WebMercator);
double len = GeometryEngine.Instance.ShapePreservingLength(pt);          // len = 0

List<MapPoint> pts = new List<MapPoint>();
pts.Add(MapPointBuilder.CreateMapPoint(1.0, 1.0, 3.0));
pts.Add(MapPointBuilder.CreateMapPoint(1.0, 3.0, 3.0));
pts.Add(MapPointBuilder.CreateMapPoint(3, 3, 3.0));
pts.Add(MapPointBuilder.CreateMapPoint(3.0, 1.0, 3.0));

// multipoint
Multipoint mPt = MultipointBuilder.CreateMultipoint(pts);
len = GeometryEngine.Instance.ShapePreservingLength(mPt);                // len = 0

// polyline
Polyline polyline = PolylineBuilder.CreatePolyline(pts, SpatialReferences.WGS84);
len = GeometryEngine.Instance.ShapePreservingLength(polyline);

// polygon
Polygon polygon = PolygonBuilder.CreatePolygon(pts, SpatialReferences.WGS84);
len = GeometryEngine.Instance.ShapePreservingLength(polygon);



polyline = PolylineBuilder.CreatePolyline(new[]
{
    MapPointBuilder.CreateMapPoint( -170, 0),
    MapPointBuilder.CreateMapPoint( 170, 0)
}, SpatialReferences.WGS84);


var length_meters = GeometryEngine.Instance.ShapePreservingLength(polyline); // , LinearUnits.Meters);
var length_miles = GeometryEngine.Instance.ShapePreservingLength(polyline, LinearUnit.Miles);

// length_meters - 37848626.869713023
// length_miles - 23518.046402579574

Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

Reference

IGeometryEngine Interface
IGeometryEngine Members
Overload List