ReverseOrientation Method (IGeometryEngine)

In This Topic

Reverse the orientation of the geometry.

Syntax

Visual Basic (Declaration)
C#

Function ReverseOrientation( _
   ByVal multipart As Multipart _
) As Multipart

Multipart ReverseOrientation( 
   Multipart multipart
)

Parameters

multipart: The polygon or polyline whose orientation will be reversed.

Return Value

A geometry whose directionality has been reversed. If the input multipart is empty, then it is returned unchanged.

Exceptions

Exception	Description
System.ArgumentNullException	Multipart is null.

Remarks

ReverseOrientation changes the direction of the curve without changing the spatial position of the curve. The From Point and To Point of each Segment are interchanged.
Caution should be taken in using ReverseOrientation on Polygons. Since ReverseOrientation changes the direction of each Ring within the Polygon, all Exterior Rings become Interior Rings and vice versa.

GeometryEngine Reverse Orientation

Example

Reverse the order of points in a Polygon

{
  List<Coordinate2D> list2D =
  [
    new Coordinate2D(1.0, 1.0),
  new Coordinate2D(1.0, 2.0),
  new Coordinate2D(2.0, 2.0),
  new Coordinate2D(2.0, 1.0),
];

  polygon = PolygonBuilderEx.CreatePolygon(list2D);

  Geometry g = GeometryEngine.Instance.ReverseOrientation(polygon);
  Polygon gPolygon = g as Polygon;

  // gPolygon.Points[0] = 1.0, 1.0
  // gPolygon.Points[1] = 2.0, 1.0
  // gPolygon.Points[2] = 2.0, 2.0
  // gPolygon.Points[3] = 1.0, 2.0
  // gPolygon.Points[4] = 1.0, 1.0
  // gPolygon.Area = -1 * polygon.Area
}

Requirements

Target Platforms: Windows 11 Home, Pro, Enterprise (64 bit)

ArcGIS Pro version: 3.0 or higher.

Reference

IGeometryEngine Interface
IGeometryEngine Members

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