Parts Property (Multipart)
Gets the parts in this instance.
Get the parts of a Polyline
int numParts = polyline.PartCount;
// get the parts as a readonly collection
ReadOnlyPartCollection parts = polyline.Parts;
Enumerate the parts of a Polyline
ReadOnlyPartCollection polylineParts = polyline.Parts;
// enumerate the segments to get the length
double len = 0;
IEnumerator<ReadOnlySegmentCollection> segments = polylineParts.GetEnumerator();
while (segments.MoveNext())
{
ReadOnlySegmentCollection seg = segments.Current;
foreach (Segment s in seg)
{
len += s.Length;
// perhaps do something specific per segment type
switch (s.SegmentType)
{
case SegmentType.Line:
break;
case SegmentType.Bezier:
break;
case SegmentType.EllipticArc:
break;
}
}
}
// or use foreach pattern
foreach (var part in polyline.Parts)
{
foreach (var segment in part)
{
len += segment.Length;
// perhaps do something specific per segment type
switch (segment.SegmentType)
{
case SegmentType.Line:
break;
case SegmentType.Bezier:
break;
case SegmentType.EllipticArc:
break;
}
}
}
StartPoint of a Polyline
// Method 1: Get the start point of the polyline by converting the polyline
// into a collection of points and getting the first point
// sketchGeometry is a Polyline
// get the sketch as a point collection
var pointCol = ((Multipart)sketchGeometry).Points;
// Get the start point of the line
var firstPoint = pointCol[0];
// Method 2: Convert polyline into a collection of line segments
// and get the "StartPoint" of the first line segment.
var polylineGeom = sketchGeometry as ArcGIS.Core.Geometry.Polyline;
var polyLineParts = polylineGeom.Parts;
ReadOnlySegmentCollection polylineSegments = polyLineParts.First();
//get the first segment as a LineSegment
var firsLineSegment = polylineSegments.First() as LineSegment;
//Now get the start Point
var startPoint = firsLineSegment.StartPoint;
Get the parts of a Polygon
// get the parts as a readonly collection
ReadOnlyPartCollection parts = polygon.Parts;
Enumerate the parts of a Polygon
int numSegments = 0;
IEnumerator<ReadOnlySegmentCollection> segments = polygon.Parts.GetEnumerator();
while (segments.MoveNext())
{
ReadOnlySegmentCollection seg = segments.Current;
numSegments += seg.Count;
foreach (Segment s in seg)
{
// do something with the segment
}
}
Get the individual parts of a multipart feature
/// <summary>
/// This method takes an input multi part geometry and breaks the parts into individual standalone geometries.
/// </summary>
/// <param name="inputGeometry">The geometry to be exploded into the individual parts.</param>
/// <returns>An enumeration of individual parts as standalone geometries. The type of geometry is maintained, i.e.
/// if the input geometry is of type Polyline then each geometry in the return is of type Polyline as well.
/// If the input geometry is of type Unknown then an empty list is returned.</returns>
public IEnumerable<Geometry> MultipartToSinglePart(Geometry inputGeometry)
{
// list holding the part(s) of the input geometry
List<Geometry> singleParts = new List<Geometry>();
// check if the input is a null pointer or if the geometry is empty
if (inputGeometry == null || inputGeometry.IsEmpty)
return singleParts;
// based on the type of geometry, take the parts/points and add them individually into a list
switch (inputGeometry.GeometryType)
{
case GeometryType.Envelope:
singleParts.Add(inputGeometry.Clone() as Envelope);
break;
case GeometryType.Multipatch:
singleParts.Add(inputGeometry.Clone() as Multipatch);
break;
case GeometryType.Multipoint:
var multiPoint = inputGeometry as Multipoint;
foreach (var point in multiPoint.Points)
{
// add each point of collection as a standalone point into the list
singleParts.Add(point);
}
break;
case GeometryType.Point:
singleParts.Add(inputGeometry.Clone() as MapPoint);
break;
case GeometryType.Polygon:
var polygon = inputGeometry as Polygon;
foreach (var polygonPart in polygon.Parts)
{
// use the PolygonBuilderEx turning the segments into a standalone
// polygon instance
singleParts.Add(PolygonBuilderEx.CreatePolygon(polygonPart));
}
break;
case GeometryType.Polyline:
var polyline = inputGeometry as Polyline;
foreach (var polylinePart in polyline.Parts)
{
// use the PolylineBuilderEx turning the segments into a standalone
// polyline instance
singleParts.Add(PolylineBuilderEx.CreatePolyline(polylinePart));
}
break;
case GeometryType.Unknown:
break;
default:
break;
}
return singleParts;
}
Target Platforms: Windows 11, Windows 10
ArcGIS Pro version: 3 or higher.