ArcObjects Library Reference (Geometry)  

IRelationalOperator Interface

Provides access to members that determine if a certain spatial relationship exists between two geometries.

Product Availability

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

Description

Relational Operators compare two geometries and return a boolean indicating whether or not the desired relationship exists.  Some relationships require that the input geometries be of the same dimension while other have more flexible dimensional constraints.  Most of the predefined Relational Operators are mutually exclusive Clementini operators. Please see the "Shape Comparison Language" topic in the Technical Documents section in the help.

When To Use

Relational Operators are used to determine whether or not a specific relationship exists between two geometries.

Members

Description
Method Contains Indicates if this geometry contains the other geometry.
Method Crosses Indicates if the two geometries intersect in a geometry of lesser dimension.
Method Disjoint Indicates if the two geometries share no points in common. Negate this result to compute the Intersect relation.
Method Equals Indicates if the two geometries are of the same type and define the same set of points in the plane.
Method Overlaps Indicates if the intersection of the two geometries has the same dimension as one of the input geometries.
Method Relation Indicates if the defined relationship exists.
Method Touches Indicates if the boundaries of the geometries intersect.
Method Within Indicates if this geometry is contained (is within) another geometry.

CoClasses that implement IRelationalOperator

CoClasses and Classes Description
Envelope A rectangle with sides parallel to a coordinate system defining the extent of another geometry; optionally has min and max measure, height and ID attributes.
GeometryBag An ordered collection of objects that support the IGeometry interface.
MultiPatch A collection of surface patches.
Multipoint An ordered collection of points; optionally has measure, height and ID attributes.
Point A 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

Only geometries that support the IRelationalOperator interface can be used as input geometries.

 

RelationalOperator Boundary/Interior Example

 

Relational operators has now been extended to support 3D polylines and that process can be generalized in three steps:

Please refer to the topic "Working with Vertical Segments" in "Learning ArcObject" section in the help.

 

 

See Also

IGeometry Interface | ITopologicalOperator Interface

.NET Samples

Geoevents in a MapControl (Code Files: GeoEvents) | Simple point plug-in data source (Code Files: SimplePointCursor) |

.NET Related Topics

Creating a plug-in data source | Executing spatial queries | Geodatabase API best practices |