QueryPoint(Multipart,SegmentExtensionType,Double,AsRatioOrLength) Method

In This Topic

Constructs a MapPointat a given distance along the curve or the extended curve.

Syntax

C#
Visual Basic (Declaration)

public MapPoint QueryPoint( 
   Multipart multipart,
   SegmentExtensionType extensionType,
   double distanceAlongCurve,
   AsRatioOrLength asRatioOrLength
)

Public Overloads Function QueryPoint( _
   ByVal multipart As Multipart, _
   ByVal extensionType As SegmentExtensionType, _
   ByVal distanceAlongCurve As Double, _
   ByVal asRatioOrLength As AsRatioOrLength _
) As MapPoint

Parameters

multipart: The multipart on which the returned point lies.
extensionType: Specifies the extension method.
distanceAlongCurve: The distance along the curve or the extended curve at which the returned point lies.
asRatioOrLength: Determines whether the distanceAlongCurve is returned as a ratio of the segment length or as length from the start point.

Return Value

The point at the given distance along the curve or extended curve.

Exceptions

Exception	Description
System.ArgumentNullException	multipartis null or empty.
System.NotImplementedException	Spatial reference of multipartis an image coordinate system.

Remarks

If the distance is less than the length of the curve, then the returned point is the point at that distance along the curve. If the distance is less than zero, or greater than the length of the curve, then the returned point is on the curve specified by the extension method. The distance may be specified as a fixed unit of measure or a ratio of the length of the curve.

Example

QueryPoint

SpatialReference sr = SpatialReferences.WGS84;

// Horizontal line segment
Coordinate2D start = new Coordinate2D(1, 1);
Coordinate2D end = new Coordinate2D(11, 1);
LineSegment line = LineBuilderEx.CreateLineSegment(start, end, sr);

Polyline polyline = PolylineBuilderEx.CreatePolyline(line);

// Don't extend the segment

MapPoint outPoint = GeometryEngine.Instance.QueryPoint(polyline, SegmentExtensionType.NoExtension, 1.0, AsRatioOrLength.AsLength);
// outPoint = (2, 1)

// or the segment
MapPoint outPoint_seg = GeometryEngine.Instance.QueryPoint(line, SegmentExtensionType.NoExtension, 1.0, AsRatioOrLength.AsLength);
// outPoint_seg = (2, 1)

// Extend infinitely in both directions
outPoint = GeometryEngine.Instance.QueryPoint(polyline, SegmentExtensionType.ExtendTangents, 1.5, AsRatioOrLength.AsRatio);
// outPoint = (16, 1)
outPoint_seg = GeometryEngine.Instance.QueryPoint(line, SegmentExtensionType.ExtendTangents, 1.5, AsRatioOrLength.AsRatio);
// outPoint_seg = (16, 1)

Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

Reference

GeometryEngine Class
GeometryEngine Members
Overload List

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