ArcObjects Library Reference (Geometry)

IEnumGeometry Interface

Provides access to members that enumerate the members of a collection of geometries.

Product Availability

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

Description

IEnumGeometry methods can be used to loop over the geometries contain in a GeometryBag or an EnumFeatureGeometry.

Members

		Description
	Count	The number of geometries in the enumeration.
	Next	Returns the next geometry in the enumeration.
	Reset	Starts the enumeration at the beginning.

CoClasses that implement IEnumGeometry

CoClasses and Classes	Description
EnumFeatureGeometry (esriGeoDatabase)	ESRI enumerator for geometries of a feature class or selection set.
GeometryBag	An ordered collection of objects that support the IGeometry interface.

[C#]

[C#]
//This example demonstrates how to use the IEnumGeometry methods
public void IEnumGeometry_Example()
{
  IGeometryBag geometryBag = CreateGeometryBag() as IGeometryBag;
  IEnumGeometry enumGeometry = geometryBag as IEnumGeometry;
  //Reset the enumrator
  enumGeometry.Reset();
  //Print the number of geometries
  System.Windows.Forms.MessageBox.Show("Number of geometries : " + enumGeometry.Count);
  //Loop over the enumerator and print the geometrytype of each geometry
  IGeometry geometry = enumGeometry.Next();
  int counter = 1;
  while(geometry != null)
  {
    System.Windows.Forms.MessageBox.Show("Geometry: " + counter + " Geometry type: " + geometry.GeometryType);
    geometry = enumGeometry.Next();
    counter++;
  }
}

//Create a geometrybag for the need of the example
private IGeometryCollection CreateGeometryBag()
{
  //Should set the spatial reference on the geometry bag here - Code ommited
  //Create some points
  IPoint[] points = new IPoint[4];
  for(int i = 0; i < 4; i++)
  {
    points[i] = new PointClass();
  }
  points[0].PutCoords(0, 0);
  points[1].PutCoords(0, 10);
  points[2].PutCoords(10, 10);
  points[3].PutCoords(0, 0);
  //Create a polyline
  IPointCollection polyLinePoints = new PolylineClass();
  //helper class to solve C-Style Array usage in COM classes
  IGeometryBridge geometryBride = new GeometryEnvironmentClass();
  geometryBride.AddPoints(polyLinePoints as IPointCollection4, ref points);
  
  //Create a polygon
  IPointCollection polygonPoints = new PolygonClass();
  geometryBride.AddPoints(polygonPoints as IPointCollection4, ref points);
  IGeometryCollection geometryBag = new GeometryBagClass();
  object Missing = Type.Missing;
  geometryBag.AddGeometry(polyLinePoints as IGeometry, ref Missing, ref Missing);
  geometryBag.AddGeometry(polygonPoints as IGeometry, ref Missing, ref Missing);
  return geometryBag;
}

[Visual Basic .NET]

    'This example demonstrates how to use the IEnumGeometry methods
    Sub IEnumGeometry_Example()
        Dim pGeoBag As ESRI.ArcGIS.Geometry.IGeometryBag, pEnumGeometry As ESRI.ArcGIS.Geometry.IEnumGeometry
        Dim pGeo As ESRI.ArcGIS.Geometry.IGeometry, i As Long
        pGeoBag = CreateGeometryBag
        pEnumGeometry = pGeoBag
        'Reset the enumrator
        pEnumGeometry.Reset()
        'Print the number of geometries
        Debug.Print("Number of geometries : " & pEnumGeometry.Count)
        'Loop over the enumerator and print the geometrytype of each geometry
        pGeo = pEnumGeometry.Next
        While Not pGeo Is Nothing
            Debug.Print("Geometry: " & i & " Geometry type: " & pGeo.GeometryType)
            i = i + 1
            pGeo = pEnumGeometry.Next
        End While
    End Sub

    'Create a geometrybag for the need of the example
    Private Function CreateGeometryBag() As ESRI.ArcGIS.Geometry.IGeometryBag
        Dim pGeoColl As ESRI.ArcGIS.Geometry.IGeometryCollection, pPointColl0 As ESRI.ArcGIS.Geometry.IPointCollection
        Dim pts(3) As ESRI.ArcGIS.Geometry.IPoint, i As Long
        Dim pPointColl1 As ESRI.ArcGIS.Geometry.IPointCollection
        pGeoColl = New ESRI.ArcGIS.Geometry.GeometryBag
        'Should set the spatial reference on the geometry bag here - Code ommited
        'Create some points
        For i = 0 To 3
            pts(i) = New ESRI.ArcGIS.Geometry.Point
        Next
        pts(0).PutCoords(0, 0)
        pts(1).PutCoords(0, 10)
        pts(2).PutCoords(10, 10)
        pts(3).PutCoords(0, 0)
        'Create a polyline
        pPointColl0 = New ESRI.ArcGIS.Geometry.Polyline
        pPointColl0.AddPoints(3, pts(0))
        'Create a polygon
        pPointColl1 = New ESRI.ArcGIS.Geometry.Polygon
        pPointColl1.AddPoints(4, pts(0))
        pGeoColl.AddGeometry(pPointColl0)
        pGeoColl.AddGeometry(pPointColl1)
        CreateGeometryBag = pGeoColl
    End Function

.NET Related Topics

Geodatabase |