Intersection(Geometry,Geometry) Method

In This Topic

Constructs the set-theoretic intersection between two geometries.

Syntax

C#
Visual Basic (Declaration)

Geometry Intersection( 
   Geometry geometry1,
   Geometry geometry2
)

Overloads Function Intersection( _
   ByVal geometry1 As Geometry, _
   ByVal geometry2 As Geometry _
) As Geometry

Parameters

geometry1: The first geometry.
geometry2: The second geometry.

Return Value

A geometry that represents the intersection of the two input geometries. The dimension of the returned geometry will be the lowest dimension of the input geometries. For example, if is a MapPoint and is a Polyline, the returned geometry will be a MapPoint. If the dimension of the intersection is not equal to the lowest dimension of the input geometries, an empty geometry will be returned. For example, suppose that is a Polyline and is a Polyline, and they cross each other at two points. The intersection is a Multipoint, but an empty Polyline will be returned. In this case, if you want the returned geometry to be the Multipoint where the input geometries intersect, use Intersection(Geometry,Geometry,GeometryDimensionType).

Exceptions

Exception	Description
System.ArgumentNullException	Either geometry1 or geometry2 or both are null or empty.
System.NotImplementedException	The method is not implemented for GeometryBag.
System.InvalidOperationException	Incompatible spatial references between the input geometries.

Remarks

If an input geometry is a Multipatch, then the Multipatch footprint will be used to determine the intersection.

GeometryEngine Intersection

Example

Intersection between two Polylines

// determine intersection between two polylines

List<MapPoint> pts = new List<MapPoint>();
pts.Add(MapPointBuilderEx.CreateMapPoint(1.0, 1.0));
pts.Add(MapPointBuilderEx.CreateMapPoint(3.0, 3.0));
pts.Add(MapPointBuilderEx.CreateMapPoint(5.0, 1.0));

Polyline line1 = PolylineBuilderEx.CreatePolyline(pts);

List<MapPoint> pts2 = new List<MapPoint>();
pts2.Add(MapPointBuilderEx.CreateMapPoint(1.0, 3.0));
pts2.Add(MapPointBuilderEx.CreateMapPoint(3.0, 1.0));
pts2.Add(MapPointBuilderEx.CreateMapPoint(5.0, 3.0));

Polyline line2 = PolylineBuilderEx.CreatePolyline(pts2);

bool intersects = GeometryEngine.Instance.Intersects(line1, line2);    // intersects = true
Geometry g = GeometryEngine.Instance.Intersection(line1, line2, GeometryDimensionType.EsriGeometry0Dimension);
Multipoint resultMultipoint = g as Multipoint;

// result is a multiPoint that intersects at (2,2) and (4,2)

Intersection between two Polygons

// determine intersection between two polygons

Envelope env1 = EnvelopeBuilderEx.CreateEnvelope(new Coordinate2D(3.0, 2.0), new Coordinate2D(6.0, 6.0));
Polygon poly1 = PolygonBuilderEx.CreatePolygon(env1);

Envelope env2 = EnvelopeBuilderEx.CreateEnvelope(new Coordinate2D(1.0, 1.0), new Coordinate2D(4.0, 4.0));
Polygon poly2 = PolygonBuilderEx.CreatePolygon(env2);

Polygon polyResult = GeometryEngine.Instance.Intersection(poly1, poly2) as Polygon;

Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

Reference

IGeometryEngine Interface
IGeometryEngine Members
Overload List

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