ArcGIS Developer Help  (GeoDatabase)    

ITopology.DirtyArea Property

The dirty area polygon of the topology. 

[Visual Basic 6.0]
Property DirtyArea(
    ByVal location As IPolygon _
) As IPolygon

[Visual Basic .NET]
Public Function get_DirtyArea ( _
    ByVal location As IPolygon _
) As IPolygon
[C#]
public IPolygon get_DirtyArea (
    IPolygon location
);
[Java]
public IPolygon getDirtyArea (
    IPolygon location
)

[C++]
HRESULT get_DirtyArea(
  IPolygon* location,
  IPolygon** dirtyAreaPolygon
);
[C++]

Parameters

location [in]

  location is a parameter of type IPolygon

dirtyAreaPolygon [out, retval]

  dirtyAreaPolygon is a parameter of type IPolygon

Product Availability

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

Description

The DirtyArea  property returns a dirty area polygon of the topology associated with the input IPolygon object.  The IPolygon can correspond to the extent of the topology or a subset of the extent.  If there is no dirty area intersecting the specified area, an empty polygon is returned.  The dirty area polygon that is returned may be a multipart polygon. Use the State property on ITopology to determine if the Topology has any dirty areas or if it has been validated.

 

Remarks

A topology has an associated dirty area or dirty areas. A dirty area corresponds to regions within the extent of the topology where features participating within the topology have been modified (added, deleted or updated) and have yet to be validated. The topological relationships between features covered by dirty areas are unknown. The dirty area must be validated inorder to discover the topological relationships and evaluate any topology rules.

Whenever the geometry or subtype of a feature participating within a topology is modified, the extent of the dirty area is enlarged to encompass the envelope of the modified feature.

[Visual Basic 6.0]

The following example demonstrates how to obtain the DirtyArea for the entire Topology.

'Assume we have a reference to a Topology called pTopo
  Dim pGeoDS As IGeoDataset
  Dim pLocation As ISegmentCollection
  Dim pPoly As IPolygon
  Dim pAreaToValidate As IEnvelope
  Dim pAreaValidated As IEnvelope
 
  'Create a new polygon object
  Set pLocation = New Polygon
 
  'QI to the IGeoDataset so we can get the extent of the Topology
  Set pGeoDS = pTopo
 
  'Set the rectangle of the pLocation polygon to be equal to the Topology extent
  pLocation.SetRectangle pGeoDS.Extent
 
  'Get the Dirty Area for the entire Topology
  Set pPoly = pTopo.DirtyArea(pLocation)

See Also

ITopology Interface

Example

ITopology DirtyArea Example

 

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