QueryPointAndDistance(Segment,SegmentExtensionType,MapPoint,AsRatioOrLength,Double,Double,LeftOrRightSide) Method

In This Topic

Finds the point on the curve closest to inPoint, then copies that point to outPoint. Also calculates related items.

Syntax

C#
Visual Basic (Declaration)

MapPoint QueryPointAndDistance( 
   Segment segment,
   SegmentExtensionType extensionType,
   MapPoint inPoint,
   AsRatioOrLength asRatioOrLength,
   out double distanceAlongCurve,
   out double distanceFromCurve,
   out LeftOrRightSide whichSide
)

Overloads Function QueryPointAndDistance( _
   ByVal segment As Segment, _
   ByVal extensionType As SegmentExtensionType, _
   ByVal inPoint As MapPoint, _
   ByVal asRatioOrLength As AsRatioOrLength, _
   ByRef distanceAlongCurve As Double, _
   ByRef distanceFromCurve As Double, _
   ByRef whichSide As LeftOrRightSide _
) As MapPoint

Parameters

segment: The curve on which to find the closest point. The curve may be extended.
extensionType: Describes if, how and where to extend segments.
inPoint: The input point.
asRatioOrLength: Determines whether the distanceAlongCurve is returned as a ratio of the curve length or as length from the start point.
distanceAlongCurve: Describes the distance from the start point of the segment to the input point, either as a ratio or length. If the input point is not on the segment, then the nearest location on the segment from the point is used.
distanceFromCurve: Describes how far the point is from the curve.
whichSide: Describes if the point is on the left or right side of the curve. The direction of the curve determines its left and right sides. If the point is on the curve, then LeftSide is returned.

Return Value

MapPoint representing the closest point on the curve.

Exceptions

Exception	Description
System.ArgumentNullException	Either segment or inPoint or both are null or empty.
System.NotImplementedException	Spatial reference of segmentis an image coordinate system.

Example

QueryPointAndDistance

// Horizontal line segment
List<MapPoint> linePts = new List<MapPoint>();
linePts.Add(MapPointBuilderEx.CreateMapPoint(1.0, 1.0, SpatialReferences.WGS84));
linePts.Add(MapPointBuilderEx.CreateMapPoint(11.0, 1.0, SpatialReferences.WGS84));
Polyline polyline = PolylineBuilderEx.CreatePolyline(linePts);
bool isSimple = GeometryEngine.Instance.IsSimpleAsFeature(polyline);

// Don't extent the segment
SegmentExtensionType extension = SegmentExtensionType.NoExtension;

// A point on the line segment
MapPoint inPoint = MapPointBuilderEx.CreateMapPoint(2, 1, SpatialReferences.WGS84);

double distanceAlongCurve, distanceFromCurve;
LeftOrRightSide whichSide;
AsRatioOrLength asRatioOrLength = AsRatioOrLength.AsLength;

MapPoint outPoint = GeometryEngine.Instance.QueryPointAndDistance(polyline, extension, inPoint, asRatioOrLength, out distanceAlongCurve, out distanceFromCurve, out whichSide);
// outPoint = 2, 1
// distanceAlongCurve = 1
// distanceFromCurve = 0
// whichSide = GeometryEngine.Instance.LeftOrRightSide.LeftSide


// Extend infinitely in both directions
extension = SegmentExtensionType.ExtendTangents;

// A point on the left side
inPoint = MapPointBuilderEx.CreateMapPoint(16, 6, SpatialReferences.WGS84);
asRatioOrLength = AsRatioOrLength.AsRatio;

outPoint = GeometryEngine.Instance.QueryPointAndDistance(polyline, extension, inPoint, asRatioOrLength, out distanceAlongCurve, out distanceFromCurve, out whichSide);
// outPoint = 16, 1
// distanceAlongCurve = 1.5
// distanceFromCurve = 5
// whichSide = GeometryEngine.Instance.LeftOrRightSide.LeftSide

Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.

Reference

IGeometryEngine Interface
IGeometryEngine Members
Overload List

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