Within Method (IGeometryEngine)

In This Topic

Returns true if geometry1 is within geometry2.

Syntax

Visual Basic (Declaration)
C#

Function Within( _
   ByVal geometry1 As Geometry, _
   ByVal geometry2 As Geometry _
) As Boolean

bool Within( 
   Geometry geometry1,
   Geometry geometry2
)

Parameters

geometry1: The base geometry.
geometry2: The comparison geometry.

Return Value

True if geometry1 is within geometry2.

Exceptions

Exception	Description
System.ArgumentNullException	Either geometry1 or geometry2 or both are null.
System.NotImplementedException	The method is not implemented for GeometryBag.
System.InvalidOperationException	Incompatible spatial references between the input geometries.

Remarks

If both geometry1 and geometry2 are not empty, then geometry1 is within geometry2 if the intersection of their interiors is not empty and geometry1 is a subset of geometry2.

If the geometry2 is empty, then geometry1 is not within geometry2.

If geometry1 is empty and geometry2 is not empty, then geometry1 is within geometry2.

Within is the opposite of Contains. That is, geometry1 is within geometry2 if and only if geometry2 contains geometry1.

GeometryEngine Within

Example

MapPoints, Polylines, Polygons within Polygon

{
    // build a polygon      
    List<MapPoint> pts =
    [
      MapPointBuilderEx.CreateMapPoint(1.0, 1.0),
  MapPointBuilderEx.CreateMapPoint(1.0, 2.0),
  MapPointBuilderEx.CreateMapPoint(2.0, 2.0),
  MapPointBuilderEx.CreateMapPoint(2.0, 1.0),
];

    Polygon poly = PolygonBuilderEx.CreatePolygon(pts);

    // an inner point
    MapPoint innerPt = MapPointBuilderEx.CreateMapPoint(1.5, 1.5);
    bool within = GeometryEngine.Instance.Within(innerPt, poly);   // within = true

    // point on a boundary
    within = GeometryEngine.Instance.Within(pts[0], poly);     // within = false

    // an interior line
    MapPoint innerPt2 = MapPointBuilderEx.CreateMapPoint(1.25, 1.75);
    List<MapPoint> innerLinePts = [innerPt, innerPt2];

    polyline = PolylineBuilderEx.CreatePolyline(innerLinePts);
    within = GeometryEngine.Instance.Within(polyline, poly);   // within = true

    // a line that crosses the boundary
    MapPoint outerPt = MapPointBuilderEx.CreateMapPoint(3, 1.5);
    List<MapPoint> crossingLinePts = [innerPt, outerPt];

    polyline = PolylineBuilderEx.CreatePolyline(crossingLinePts);
    within = GeometryEngine.Instance.Within(polyline, poly);     // within = false

    // polygon in polygon
    Envelope env = EnvelopeBuilderEx.CreateEnvelope(innerPt, innerPt2);
    within = GeometryEngine.Instance.Within(env, poly);      // within = true
  }

Requirements

Target Platforms: Windows 11 Home, Pro, Enterprise (64 bit)

ArcGIS Pro version: 3.0 or higher.

Reference

IGeometryEngine Interface
IGeometryEngine Members

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