CopyPointsToList Method

In This Topic

Copies the MapPoints in this list to the given list of MapPoints.

Syntax

C#
Visual Basic (Declaration)

public void CopyPointsToList( 
   int startIndex,
   int pointCount,
   ref ICollection<MapPoint> points
)

Public Sub CopyPointsToList( _
   ByVal startIndex As Integer, _
   ByVal pointCount As Integer, _
   ByRef points As ICollection(Of MapPoint) _
)

Parameters

startIndex: The index of the first point to copy.
pointCount: The number of points to copy.
points: The list into which the points are copied. Each returned point in the list has a null spatial reference.

Exceptions

Exception	Description
System.ArgumentNullException	points is null.
System.ArgumentException	pointCount is less than zero.
System.ArgumentOutOfRangeException	startIndex + pointCount is greater than the actual number of points in this list.

Remarks

Use this method to get a list of points of a geometry on which low-level calculations may be performed. Performance may be improved by reusing the same list for each geometry. For optimal performance, the collection should have a capacity greater than or equal to the number of points that are to be copied.

Example

Get the points of a Polyline

// get the points as a readonly Collection
ReadOnlyPointCollection pts = polyline.Points;
int numPts = polyline.PointCount;

// OR   get an enumeration of the points
IEnumerator<MapPoint> enumPts = polyline.Points.GetEnumerator();

// OR   get the point coordinates as a readonly list of Coordinate2D
IReadOnlyList<Coordinate2D> coordinates = polyline.Copy2DCoordinatesToList();

// OR   get the point coordinates as a readonly list of Coordinate3D
IReadOnlyList<Coordinate3D> coordinates3D = polyline.Copy3DCoordinatesToList();

// OR   get a subset of the collection as Coordinate2D using preallocated memory

IList<Coordinate2D> coordinate2Ds = new List<Coordinate2D>(10);   // allocate some space
ICollection<Coordinate2D> subsetCoordinates2D = coordinate2Ds;    // assign
pts.Copy2DCoordinatesToList(1, 2, ref subsetCoordinates2D);       // copy 2 elements from index 1 into the allocated list
                                                                  // coordinate2Ds.Count = 2
                                                                  // do something with the coordinate2Ds

// without allocating more space, obtain a different set of coordinates
pts.Copy2DCoordinatesToList(5, 9, ref subsetCoordinates2D);       // copy 9 elements from index 5 into the allocated list
                                                                  // coordinate2Ds.Count = 9


// OR   get a subset of the collection as Coordinate3D using preallocated memory

IList<Coordinate3D> coordinate3Ds = new List<Coordinate3D>(15);   // allocate some space
ICollection<Coordinate3D> subsetCoordinates3D = coordinate3Ds;    // assign
pts.Copy3DCoordinatesToList(3, 5, ref subsetCoordinates3D);       // copy 5 elements from index 3 into the allocated list
                                                                  // coordinate3Ds.Count = 5


// OR   get a subset of the collection as MapPoint using preallocated memory

IList<MapPoint> mapPoints = new List<MapPoint>(7);   // allocate some space
ICollection<MapPoint> subsetMapPoint = mapPoints;    // assign
pts.CopyPointsToList(1, 4, ref subsetMapPoint);      // copy 4 elements from index 1 into the allocated list
                                                     // mapPoints.Count = 4

Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.

Reference

ReadOnlyPointCollection Class
ReadOnlyPointCollection Members

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