ITopologicalOperator Interface

Provides access to members for constructing new geometries based upon topological relationships between existing geometries.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Members

		Description
	Boundary	The boundary of this geometry. A polygon's boundary is a polyline. A polyline's boundary is a multipoint. A point or multipoint's boundary is an empty point or multipoint.
	Buffer	Constructs a polygon that is the locus of points at a distance less than or equal to a specified distance from this geometry.
	Clip	Constructs the intersection of this geometry and the specified envelope.
	ClipDense	Constructs the intersection of this geometry and the specified envelope; densifies lines in output contributed by the clipping envelope.
	ConstructUnion	Defines this geometry to be the union of the inputs. More efficient for unioning multiple geometries than calling Union repeatedly.
	ConvexHull	Constructs the convex hull of this geometry.
	Cut	Splits this geometry into a part left of the cutting polyline, and a part right of it.
	Difference	Constructs the geometry containing points from this geometry but not the other geometry.
	Intersect	Constructs the geometry that is the set-theoretic intersection of the input geometries. Use different resultDimension values to generate results of different dimensions.
	IsKnownSimple	Indicates whether this geometry is known (or assumed) to be topologically correct.
	IsSimple	Indicates whether this geometry is known (or assumed) to be topologically correct, after explicitly determining this if the geometry is not already known (or assumed) to be simple.
	QueryClipped	Redefines clippedGeometry to be the intersection of this geometry and the clipping envelope.
	QueryClippedDense	Redefines clippedGeometry to be the intersection of this geometry and the clipping envelope; densifies lines in the output contributed by the clipping envelope.
	Simplify	Makes this geometry topologically correct.
	SymmetricDifference	Constructs the geometry that contains points from either but not both input geometries.
	Union	Constructs the geometry that is the set-theoretic union of the input geometries.

CoClasses that implement ITopologicalOperator

CoClasses and Classes	Description
GeoEllipse (esriMilitaryAnalyst)	A spheroidal ellipse.
GeometryBag	An ordered collection of objects that support the IGeometry interface.
GeoPolygon (esriMilitaryAnalyst)	A spheroidal polygon.
GeoPolyline (esriMilitaryAnalyst)	A spheroidal polyline.
MultiPatch	A collection of surface patches.
Multipoint	An ordered collection of points; optionally has measure, height and ID attributes.
Point	An two dimensional point, optionally with measure, height, and ID attributes.
Polygon	A collection of rings ordered by their containment relationship; optionally has measure, height and ID attributes.
Polyline	An ordered collection of paths; optionally has measure, height and ID attributes.

Remarks

The Buffer, Clip, and Simplify methods only are supported on GeometryBags.

ITopologicalOperator methods must be applied on high-level geometries only. High-Level geometries are point, multipoint, polyline and polygon. To use this method with low-level geometries such as segments (Line, Circular Arc, Elliptic Arc, Bézier Curve), paths or rings, they must be wrapped into high-level geometries types.

[C#]

//The following code shows to wrap a line segment into a polyline in C#

//Assume a line (line1 as ILine) is already created

object obj = Type.Missing;

ISegmentCollection segCollection = new PolylineClass() as ISegmentCollection;

segCollection.AddSegment((ISegment)line1, ref obj, ref obj);

//Set the spatial reference on the new polyline

//The spatial reference is not transfered automatically from the segments

IGeometry geom = segCollection as IGeometry;

geom.SpatialReference = spatialRef;

//Can now be used with ITopologicalOperator3 methods

[Visual Basic 6.0]

'How to wrap a line segment into a polyline in VB6
'Assume a line (pLine as ILine) is already created
Dim psc as ISegmentCollection
Set psc = New Polyline
psc.addsegment pline
'Set the spatial reference on the new polyline
'The spatial reference is not transfered automatically from the segments
dim pgeo as IGeometry
set pgeo = psc
set pgeo.SpatialReference = pMyspatialReference

'Can now be used with ITopologicalOperator methods

Example

Share_a_line_segment

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