ArcObjects Library Reference (Geometry)

ICurve Interface

Provides access to properties and methods of all 1 dimensional curves (polylines, segments, boundaries of polygons, etc.). Note: the ICurve interface has been superseded byICurve3. Please consider using the more recent version.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Description

A curve is an abstract one-dimensional geometry between specific From and To points. A curve can be composed of a single Segment, a Path of connected segments, or a Polycurve containing many paths of segments. The properties and methods of the curve allow the user to query information about the entire curve or points along the curve. The distance along the curve can be specified in a fixed unit of measure or as a ratio of the Length of the curve. The user can obtain information about Tangents, Normals, Subcurves, and Points along the curve.

Members

		Description
	Dimension	The topological dimension of this geometry.
	Envelope	Creates a copy of this geometry's envelope and returns it.
	FromPoint	The 'from' point of the curve.
	GeometryType	The type of this geometry.
	GeoNormalize	Shifts longitudes, if need be, into a continuous range of 360 degrees.
	GeoNormalizeFromLongitude	Normalizes longitudes into a continuous range containing the longitude. This method is obsolete.
	GetSubcurve	Extracts a portion of this curve into a new curve.
	IsClosed	Indicates if 'from' and 'to' points (of each part) are identical.
	IsEmpty	Indicates whether this geometry contains any points.
	Length	The length of the curve.
	Project	Projects this geometry into a new spatial reference.
	QueryEnvelope	Copies this geometry's envelope properties into the specified envelope.
	QueryFromPoint	Copies this curve's 'from' point to the input point.
	QueryNormal	Constructs a line normal to a curve from a point at a specified distance along the curve.
	QueryPoint	Copies to outPoint the properties of a point on the curve at a specified distance from the beginning of the curve.
	QueryPointAndDistance	Finds the point on the curve closest to inPoint, then copies that point to outPoint; optionally calculates related items.
	QueryTangent	Constructs a line tangent to a curve from a point at a specified distance along the curve.
	QueryToPoint	Copies the curve's 'to' point into the input point.
	ReverseOrientation	Reverses the parameterization of the curve ('from' point becomes 'to' point, first segment becomes last segment, etc).
	SetEmpty	Removes all points from this geometry.
	SnapToSpatialReference	Moves points of this geometry so that they can be represented in the precision of the geometry's associated spatial reference system.
	SpatialReference	The spatial reference associated with this geometry.
	ToPoint	The 'to' point of the curve.

Inherited Interfaces

Interfaces	Description
IGeometry	Provides access to members that describe properties and behavior of all geometric objects.

CoClasses that implement ICurve

CoClasses and Classes	Description
BezierCurve	A cubic Bezier curve defined between two points; optionally has measure, height and ID attributes at each endpoint.
CircularArc	A portion of a circle that connects two points optionally has measure, height and ID attributes at each endpoint.
EllipticArc	A portion of the boundary of a 2D ellipse that connects two points; optionally has measure, height and ID attributes at each endpoint.
Line	A 2D straight line between a pair of 2D endpoints; can optionally have height, measure and ID attributes at each endpoint.
Path	A sequence of connected segments.
Polygon	A collection of rings ordered by their containment relationship; optionally has measure, height and ID attributes.
Polyline	An ordered collection of paths; optionally has measure, height and ID attributes.
Ring	An area bounded by one, closed sequence of connected segments; optionally has measure, height and ID attributes at each vertex.

[C#]

//The example shows how to get the ICurve properties of a polygon feature
public void GetCurveProperties(IFeature currentFeature)
{
    if (currentFeature.Shape.GeometryType == esriGeometryType.esriGeometryPolygon)
    {
        ICurve curve=currentFeature.Shape as ICurve;
        System.Windows.Forms.MessageBox.Show("Polygon::ICurve properties..." + "\n" +
        "Curve.Length=" + curve.Length + "\n" +
        "Curve.IsClosed=" + curve.IsClosed + "\n" +
        "Curve.FromPoint.X=" + curve.FromPoint.X + "\n" +
        "Curve.FromPoint.Y=" + curve.FromPoint.Y + "\n" +
        "Curve.ToPoint.X=" + curve.ToPoint.X + "\n" +
        "Curve.ToPoint.Y=" + curve.ToPoint.Y
        );
    }
}

[Visual Basic .NET]

    ' The example shows how to get the ICurve properties of a polygon feature
    Public Sub t_ICurve_polygon(ByVal pFeature As IFeature)
        Dim pCurve As ICurve
        If pFeature.Shape.GeometryType=esriGeometryType.esriGeometryPolygon Then
            pCurve=pFeature.Shape
            MsgBox("+++Polygon::ICurve properties..." & vbCrLf _
              & "Curve.Length=" & pCurve.Length & vbCrLf _
              & "Curve.IsClosed=" & pCurve.IsClosed _
              & "Curve.FromPoint.X=" & pCurve.FromPoint.X & vbCrLf _
              & "Curve.FromPoint.Y=" & pCurve.FromPoint.Y & vbCrLf _
              & "Curve.ToPoint.X=" & pCurve.ToPoint.X & vbCrLf _
              & "Curve.ToPoint.Y=" & pCurve.ToPoint.Y)
        End If
    End Sub

.NET Snippets

Flip Line Direction

.NET Samples

Curve conversion add-in (Code Files: CurveConversionDockWin) | Tabbed feature inspector (Code Files: TabbedInspector) | Move a graphic along a path in ArcMap (Code Files: AnimationUtils) | ArcGIS Network Analyst extension barrier location editor (Code Files: EditorForm) | Tabbed feature inspector (Code Files: ObjectInspector)