Boundary Method (IGeometryEngine)

In This Topic

Calculates the boundary of the input geometry.

Syntax

C#
Visual Basic (Declaration)

Geometry Boundary( 
   Geometry geometry
)

Function Boundary( _
   ByVal geometry As Geometry _
) As Geometry

Parameters

geometry: Specifies the input geometry.

Return Value

The geometry that represents the boundary of the input geometry. For Point - returns an empty point. For Multipoint - returns an empty point. For Envelope - returns a polyline, that bounds the envelope. For Polyline - returns a multipoint, using OGC specification (includes path endpoints, using mod 2 rule). For Polygon - returns a polyline that bounds the polygon by adding all rings of the polygon to a polyline.

Exceptions

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

Remarks

GeometryEngine Boundary

Example

Determine the boundary of a multi-part Polygon

// create a donut polygon.  Must use the PolygonBuilderEx object

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

List<Coordinate2D> innerPts = new List<Coordinate2D>();
innerPts.Add(new Coordinate2D(13.0, 13.0));
innerPts.Add(new Coordinate2D(17.0, 13.0));
innerPts.Add(new Coordinate2D(17.0, 17.0));
innerPts.Add(new Coordinate2D(13.0, 17.0));

Polygon donut = null;

// add the outer points
PolygonBuilderEx pb = new PolygonBuilderEx(outerPts);
// add the inner points (note they are defined anticlockwise)
pb.AddPart(innerPts);
// get the polygon
donut = pb.ToGeometry();

// get the boundary 
Geometry g = GeometryEngine.Instance.Boundary(donut);
Polyline boundary = g as Polyline;

Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

Reference

IGeometryEngine Interface
IGeometryEngine Members

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