ArcGIS Pro 2.8 API Reference Guide

Polygon Class

A class representing a polygon.

Object Model

Syntax

Remarks

A polygon is defined by a collection of rings. Each ring is a collection of contiguous segments such that the start point and the end point of each Segment are the same (that is it is a closed ring). If a polygon has more than one ring, the rings may be separate from one another or they may nest inside one another, but they should not overlap. Access the rings of a polygon using the Multipart.Parts method.

Note: For a polygon to be topologically correct, exterior rings should be clockwise and interior rings should be counterclockwise. If there is ever a doubt about the topological correctness of a polygon, call the GeometryEngine.SimplifyAsFeature method to correct any issues.

The boundary of a polygon is the collection of rings by which the polygon is defined. The boundary contains one or more outer rings and zero or more inner rings. An outer ring is oriented clockwise while an inner ring is oriented counter-clockwise. Imagine walking clockwise along an outer ring. The area to your immediate right is the interior of the polygon and to your left is the exterior. Similarly, if you were to walk counter-clockwise along an inner ring, the area to your immediate right is the interior of the polygon and to your left is the exterior.

A Polygon is based upon the parent Geometry class. The Geometry class is immutable which means that you can not change its shape once it is created. If you need to modify a Polygon once it has been created, use the PolygonBuilder class instead. The PolygonBuilder.ToGeometry method will provide you with the Polygon object.

Inheritance Hierarchy

System.Object

ArcGIS.Core.Geometry.Geometry

ArcGIS.Core.Geometry.Multipart

**ArcGIS.Core.Geometry.Polygon**

Requirements

**Target Platforms: **Windows 10, Windows 8.1

See Also