ArcObjects Library Reference (Geometry)

IPolygon Interface

Provides access to members that identify a polygon and permit controlled access to its inner and outer rings. Note: the IPolygon interface has been superseded byIPolygon4. Please consider using the more recent version.

Product Availability

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

Description

A polygon is a collection of one or many exterior and interior rings. The rings do not need to be connected to or contained by other rings in the polygon. However, all rings are considered to be part of a single polygon regardless of their location. Rings can be embedded in the interior of other rings. Embedded rings define interior boundaries or holes within the polygon. Exterior rings are oriented in a clockwise direction while interior rings are oriented counterclockwise.

Members

		Description
	Close	Closes all rings in this polygon. The resulting polygon may not be simple.
	Densify	Converts this polycurve into a piecewise linear approximation of itself.
	Dimension	The topological dimension of this geometry.
	Envelope	Creates a copy of this geometry's envelope and returns it.
	ExteriorRingCount	The number of exterior rings.
	FindExteriorRing	Returns the exterior ring containing the specified interior ring.
	FromPoint	The 'from' point of the curve.
	Generalize	Generalizes this polycurve using the Douglas-Poiker algorithm.
	GeometryType	The type of this geometry.
	GeoNormalize	Shifts longitudes, if need be, into a continuous range of 360 degrees.
	GeoNormalizeFromLongitude	Normalizes longitudes into a continuous range containing the longitude. This method is obsolete.
	GetSubcurve	Extracts a portion of this curve into a new curve.
	InteriorRingCount	The number of rings interior to the specified exterior ring.
	IsClosed	Indicates if 'from' and 'to' points (of each part) are identical.
	IsEmpty	Indicates whether this geometry contains any points.
	Length	The length of the curve.
	Project	Projects this geometry into a new spatial reference.
	QueryEnvelope	Copies this geometry's envelope properties into the specified envelope.
	QueryExteriorRings	Populates an array with references to all exterior rings. This method does not marshall correctly out-of-proc. Use QueryExteriorRingsEx on the IPolygon2 interface instead.
	QueryFromPoint	Copies this curve's 'from' point to the input point.
	QueryInteriorRings	Populates an array with references to rings that are interior to the specified exterior ring. This method does not marshall correctly out-of-proc. Use QueryInteriorRingsEx on the IPolygon2 interface instead.
	QueryNormal	Constructs a line normal to a curve from a point at a specified distance along the curve.
	QueryPoint	Copies to outPoint the properties of a point on the curve at a specified distance from the beginning of the curve.
	QueryPointAndDistance	Finds the point on the curve closest to inPoint, then copies that point to outPoint; optionally calculates related items.
	QueryTangent	Constructs a line tangent to a curve from a point at a specified distance along the curve.
	QueryToPoint	Copies the curve's 'to' point into the input point.
	ReverseOrientation	Reverses the parameterization of the curve ('from' point becomes 'to' point, first segment becomes last segment, etc).
	SetEmpty	Removes all points from this geometry.
	SimplifyPreserveFromTo	Simplifies the polygon and maintains the index location of the from/to point of each ring.
	Smooth	Converts this curve into a smooth curve containing only Bezier curve segments.
	SnapToSpatialReference	Moves points of this geometry so that they can be represented in the precision of the geometry's associated spatial reference system.
	SpatialReference	The spatial reference associated with this geometry.
	SplitAtDistance	Introduces a new vertex into this polyline at a specified distance from the beginning of the polyline.
	SplitAtPoint	Introduces a new vertex into this polyline at the location on it closest to the input point.
	ToPoint	The 'to' point of the curve.
	Weed	Generalizes using a small tolerance based upon either the system units of the geometry's spatial reference, or the geometry's bounding box.

Inherited Interfaces

Interfaces	Description
IPolycurve	Provides access to members that define operations common to polylines and the boundaries of polygons.
ICurve	Provides access to properties and methods of all 1 dimensional curves (polylines, segments, boundaries of polygons, etc.).
IGeometry	Provides access to members that describe properties and behavior of all geometric objects.

CoClasses that implement IPolygon

CoClasses and Classes	Description
GeoEllipse (esriDefenseSolutions)	Its a spheroidal ellipse.
GeoPolygon (esriDefenseSolutions)	Its a spheroidal polygon.
Polygon	A collection of rings ordered by their containment relationship; optionally has measure, height and ID attributes.

Remarks

To define a polygon containing many disjoint rings, the polygon must be defined as a GeometryCollection to which preconstructed ring geometries are added. Adding segments to a polygon defined as a SegmentCollection, or points to a polygon defined as a PointCollection, assumes that the polygon is a single ring of connected segments.

IPolygon2 extends the functionality of IPolygon.

Polygons