ArcObjects Library Reference (Geometry)

ITopologicalOperator.Difference Method

Constructs the geometry containing points from this geometry but not the other geometry.

[Visual Basic .NET]
Public Function Difference ( _
    ByVal other As IGeometry _
) As IGeometry

[C#]
public IGeometry Difference (
    IGeometry other
);

[C++]
HRESULT Difference(
  IGeometry* other,
  IGeometry** resultGeom
);

[C++]

Parameters
other 

  other is a parameter of type IGeometry
resultGeom [out, retval]

  resultGeom is a parameter of type IGeometry

Product Availability

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

Description

Difference create a Geometry that is composed only of the region unique to the base geometry but not part of the input geometry.

Remarks

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.

This method does not support GeometryBags.

ITopologicalOperator Differenece Example

[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 ITopologicalOperator methods

ITopologicalOperator.Difference Method

Product Availability

Description

Remarks

See Also