NearestPoint Method (GeometryEngine)
Finds the nearest point in the geometry to a specified point.
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.
Nearest Point versus Nearest Vertex
SpatialReference sr = SpatialReferences.WGS84;
MapPoint pt = MapPointBuilderEx.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 = PolygonBuilderEx.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
Target Platforms: Windows 11, Windows 10
ArcGIS Pro version: 3.0 or higher.