ArcGIS Pro 3.3 API Reference Guide
ArcGIS.Core.Geometry Namespace / Polygon Class / GetExteriorRings Method
(Optional) Determines if the spatial reference should be set in each of the returned polygons. If setSpatialReference is set to true, then the spatial reference in each polygon is inherited from this polygon. If setSpatialReference is set to false, then the spatial reference in each polygon is set to null. The default value is true.
Example

In This Topic
    GetExteriorRings Method
    In This Topic
    Gets all of the exterior rings in this polygon.
    Syntax
    public IList<Polygon> GetExteriorRings( 
       bool setSpatialReference
    )
    Public Function GetExteriorRings( _
       Optional ByVal setSpatialReference As Boolean _
    ) As IList(Of Polygon)

    Parameters

    setSpatialReference
    (Optional) Determines if the spatial reference should be set in each of the returned polygons. If setSpatialReference is set to true, then the spatial reference in each polygon is inherited from this polygon. If setSpatialReference is set to false, then the spatial reference in each polygon is set to null. The default value is true.

    Return Value

    A list of polygons representing the exterior rings in this polygon.
    Remarks
    An exterior ring is a part that is oriented clockwise.
    Example
    Get the exterior rings of a polygon - polygon.GetExteriorRing
    public void GetExteriorRings(Polygon inputPolygon)
    {
      if (inputPolygon == null || inputPolygon.IsEmpty)
        return;
    
      // polygon part count
      int partCount = inputPolygon.PartCount;
      // polygon exterior ring count
      int numExtRings = inputPolygon.ExteriorRingCount;
      // get set of exterior rings for the polygon
      IList<Polygon> extRings = inputPolygon.GetExteriorRings();
    
      // test each part for "exterior ring"
      for (int idx = 0; idx < partCount; idx++)
      {
        bool isExteriorRing = inputPolygon.IsExteriorRing(idx);
        var ring = inputPolygon.GetExteriorRing(idx);
      }
    }
    Requirements

    Target Platforms: Windows 11, Windows 10

    ArcGIS Pro version: 3 or higher.
    See Also