GetSubCurve Method (IGeometryEngine)

In This Topic

Gets the subcurve of the input multipart between fromDistance and toDistance.

Syntax

Visual Basic (Declaration)
C#

Function GetSubCurve( _
   ByVal multipart As Multipart, _
   ByVal fromDistance As Double, _
   ByVal toDistance As Double, _
   ByVal asRatioOrLength As AsRatioOrLength _
) As Polyline

Polyline GetSubCurve( 
   Multipart multipart,
   double fromDistance,
   double toDistance,
   AsRatioOrLength asRatioOrLength
)

Parameters

multipart: The multipart from which the subcurve will be extracted.
fromDistance: The distance along the multipart to start the subcurve.
toDistance: The distance along the multipart to end the subcurve.
asRatioOrLength: Indicates whether the fromDistance and toDistance are given as lengths or ratios along the multipart.

Return Value

The polyline representing the subcurve. If the input multipart is empty, then an empty polyline is returned.

Exceptions

Exception	Description
System.ArgumentNullException	Multipart is null.

Example

Get Sub-curve of a polyline or polygon

{
  SpatialReference sr = SpatialReferences.WGS84;

  List<Coordinate2D> coords =
  [
    new Coordinate2D(-111, 72),
  new Coordinate2D(-108, 68),
  new Coordinate2D(-114, 68)
  ];

  polyline = PolylineBuilderEx.CreatePolyline(coords, sr);

  Polyline subCurve = GeometryEngine.Instance.GetSubCurve(polyline, 0, 5, AsRatioOrLength.AsLength);
  // subCurve.PartCount = 1
  // subCurve.PointCount = 2

  ReadOnlyPointCollection points = subCurve.Points;
  // points[0] = -111, 72
  // points[1] = -108, 68

  subCurve = GeometryEngine.Instance.GetSubCurve(polyline, 0, 0.5, AsRatioOrLength.AsRatio);
  // subCurve.PointCount = 3

  points = subCurve.Points;
  // points[0] = -111, 72
  // points[1] = -108, 68
  // points[2] = -108.5, 68

  List<Coordinate3D> coords3D =
  [
    new Coordinate3D(0, 0, 0),
  new Coordinate3D(0, 1, 1),
  new Coordinate3D(1, 1, 2),
  new Coordinate3D(1, 0, 3)
  ];

  polygon = PolygonBuilderEx.CreatePolygon(coords3D, sr);

  subCurve = GeometryEngine.Instance.GetSubCurve3D(polygon, 0, 1, AsRatioOrLength.AsLength);
  // subCurve.HasZ = true

  points = subCurve.Points;
  // points.Count = 2
  // points[0] = 0, 0, 0
  // points[1] = 0, 0.70710678118654746, 0.70710678118654746
}

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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