ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Core.Geometry Namespace / MultipartBuilderEx Class / ReverseOrientation Method
Example Version

ReverseOrientation Method (MultipartBuilderEx)
Changes the direction of the parts without changing the spatial position of the parts. The start point and end point of each segment in each part are interchanged.
Syntax
public void ReverseOrientation()
Remarks
Caution should be taken when using ReverseOrientation on polygons. Since ReverseOrientation changes the direction of each part within the polygon, all exterior rings become interior rings and vice versa.

GeometryEngine Reverse Orientation

Example
Reverse the order of points in a Polyline
var polylineBuilder = new PolylineBuilderEx(polyline);
polylineBuilder.ReverseOrientation();
Polyline reversedPolyline = polylineBuilder.ToGeometry();
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also