Within Method (IGeometryEngine)

In This Topic

Returns true if geometry1 is within geometry2.

Syntax

C#
Visual Basic (Declaration)

bool Within( 
   Geometry geometry1,
   Geometry geometry2
)

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

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 or empty.
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 = new List<MapPoint>();
pts.Add(MapPointBuilderEx.CreateMapPoint(1.0, 1.0));
pts.Add(MapPointBuilderEx.CreateMapPoint(1.0, 2.0));
pts.Add(MapPointBuilderEx.CreateMapPoint(2.0, 2.0));
pts.Add(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 = new List<MapPoint>();
innerLinePts.Add(innerPt);
innerLinePts.Add(innerPt2);

Polyline 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 = new List<MapPoint>();
crossingLinePts.Add(innerPt);
crossingLinePts.Add(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, Windows 10, Windows 8.1

Reference

IGeometryEngine Interface
IGeometryEngine Members

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