ArcGIS Pro 2.6 API Reference Guide
SideBuffer(IEnumerable<Polyline>,Double,LeftOrRightSide,LineCapType) Method
Example 

ArcGIS.Core.Geometry Namespace > IGeometryEngine Interface > SideBuffer Method : SideBuffer(IEnumerable<Polyline>,Double,LeftOrRightSide,LineCapType) Method
The polylines to buffer
The buffer distance
The side of the polyline to create the buffer
The line caps
Constructs a buffer on one side of a polyline
Syntax

Parameters

polylines
The polylines to buffer
distance
The buffer distance
side
The side of the polyline to create the buffer
caps
The line caps

Return Value

List of geometries representing the side buffers
Exceptions
ExceptionDescription
Geometries is null or empty
The buffer distance must be a valid floating point number.
The method is not implemented for LineCapType.Square.
Remarks
The spatial reference of the output geometries is the first not null or Unknown spatial reference found in the list of geometries. All other geometries are projected to this spatial reference, if necessary. If no such spatial reference is found, then the Unknown spatial reference is used if it is found in the list. Otherwise, the spatial reference is null.
Example
SpatialReference spatialReference = SpatialReferenceBuilder.CreateSpatialReference(102010);
List<Coordinate2D> coordinates = new List<Coordinate2D>()
{
  new Coordinate2D(1200, 5800),
  new Coordinate2D(1400, 5800),
  new Coordinate2D(1400, 6000),
  new Coordinate2D(1300, 6000),
  new Coordinate2D(1300, 5700)
};

Polyline polyline1 = PolylineBuilder.CreatePolyline(coordinates, spatialReference);

coordinates.Clear();
coordinates.Add(new Coordinate2D(1400, 6050));
coordinates.Add(new Coordinate2D(1600, 6150));
coordinates.Add(new Coordinate2D(1800, 6050));

Polyline polyline2 = PolylineBuilder.CreatePolyline(coordinates, spatialReference);
List<Polyline> polylines = new List<Polyline>() { polyline1, polyline2 };
IReadOnlyList<Geometry> outGeometries = GeometryEngine.Instance.SideBuffer(polylines, 10, LeftOrRightSide.RightSide, LineCapType.Round);
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

IGeometryEngine Interface
IGeometryEngine Members
Overload List