ArcGIS Pro 2.9 API Reference Guide
NearestPoint Method (GeometryEngine)
Example 

ArcGIS.Core.Geometry Namespace > GeometryEngine Class : NearestPoint Method
The geometry.
The point to which the returned point will be nearest.
Finds the nearest point in the geometry to a specified point.
Syntax
public ProximityResult NearestPoint( 
   Geometry geometry,
   MapPoint point
)
Public Function NearestPoint( _
   ByVal geometry As Geometry, _
   ByVal point As MapPoint _
) As ProximityResult

Parameters

geometry
The geometry.
point
The point to which the returned point will be nearest.

Return Value

ProximityResult.

If the input geometry is a Point, then ProximityResult.PointIndex = 0, ProximityResult.PartIndex = 0, and ProximityResult.SegmentIndex is null.

If the input geometry is a Multipoint, ProximityResult.PointIndex is the index of the nearest point in the Multipoint, ProximityResult.PartIndex = ProximityResult.PointIndex, and ProximityResult.SegmentIndex is null.

Otherwise, ProximityResult.PointIndex is null and ProximityResult.SegmentIndex is the segment which contains the nearest point. The segment index is relative to the ProximityResult.PartIndex. For example, if the segment index = 0 and the part index = 2, then the segment containing the nearest point is segment 0 of part 2. In other words, the segment is the first segment of the third part.

Proximity.RightSide specifies if the input query point is on the right side of the input geometry or not.

Exceptions
ExceptionDescription
Either geometry or point or both are null or empty.
The method is not implemented for GeometryBag.
This function is not implemented for envelopes.
Remarks
The nearest point does not have to be a vertex of the input geometry. It can be any point on the geometry. If the geometry is a Polygon, then the nearest point will be a point on the boundary of the Polygon.

GeometryEngine NearestPoint

Example
SpatialReference sr = SpatialReferences.WGS84;
MapPoint pt = MapPointBuilder.CreateMapPoint(5, 5, sr);

List<Coordinate2D> coords = new List<Coordinate2D>()
{
  new Coordinate2D(10, 1),
  new Coordinate2D(10, -4),
  new Coordinate2D(0, -4),
  new Coordinate2D(0, 1),
  new Coordinate2D(10, 1)
};

Polygon polygon = PolygonBuilder.CreatePolygon(coords);

// find the nearest point in the polygon geomtry to the pt
ProximityResult result = GeometryEngine.Instance.NearestPoint(polygon, pt);
// result.Point = 5, 1
// result.SegmentIndex = 3
// result.PartIndex = 0
// result.PointIndex = null
//result.Distance = 4
//result.RightSide = false

// find the nearest vertex in the polgyon geometry to the pt
result = GeometryEngine.Instance.NearestVertex(polygon, pt);
// result.Point = 10, 1
// result.PointIndex = 0
// result.SegmentIndex = null
// result.PartIndex = 0
// result.Distance = Math.Sqrt(41)
// result.RightSide = false
Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

See Also

Reference

GeometryEngine Class
GeometryEngine Members