ArcGIS Pro 2.7 API Reference Guide
EllipticArcBuilder Constructor(MapPoint,MapPoint,Coordinate2D,esriArcOrientation,SpatialReference)
Example 

ArcGIS.Core.Geometry Namespace > EllipticArcBuilder Class > EllipticArcBuilder Constructor : EllipticArcBuilder Constructor(MapPoint,MapPoint,Coordinate2D,esriArcOrientation,SpatialReference)
The point from which the arc starts.
The point to which the arc ends.
The center point of the embedded circle.
The orientation of the arc, clockwise or counterclockwise.
(Optional) The spatial reference of the arc. The default value is null.
Builds a new instance of the EllipticArcBuilder class. The new instance will be a circular arc from end points and the center point. This method must be called on the MCT. Use QueuedTask.Run.
Syntax

Parameters

startPt
The point from which the arc starts.
endPt
The point to which the arc ends.
centerPt
The center point of the embedded circle.
orientation
The orientation of the arc, clockwise or counterclockwise.
spatialReference
(Optional) The spatial reference of the arc. The default value is null.
Exceptions
ExceptionDescription
Incompatible spatial references.
This method or property must be called within the lambda passed to QueuedTask.Run.
startPt or endPt is null.
Remarks
The xy-tolerance from the spatial reference is used to create the elliptic arc. If the spatial reference is null, then a default tolerance is used which may cause unexpected results.
Example
// Construct a circular arc from (2, 1) to (1, 2) 
// with center point at (1, 1) and orientation counterclockwise.
// Use a builder convenience method or use a builder constructor.

MapPoint toPt = MapPointBuilder.CreateMapPoint(1, 2);
MapPoint fromPt = MapPointBuilder.CreateMapPoint(2, 1);
Coordinate2D centerPtCoord = new Coordinate2D(1, 1);

// Builder convenience methods don't need to run on the MCT.
EllipticArcSegment circularArc = EllipticArcBuilder.CreateEllipticArcSegment(fromPt, toPt, centerPtCoord, esriArcOrientation.esriArcCounterClockwise);

// Builder constructors need to run on the MCT.
ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
{
  using (EllipticArcBuilder cab = new EllipticArcBuilder(fromPt, toPt, centerPtCoord, esriArcOrientation.esriArcCounterClockwise))
  {
    // do something with the builder

    EllipticArcSegment otherCircularArc = cab.ToSegment();
  }
});
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

EllipticArcBuilder Class
EllipticArcBuilder Members
Overload List