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This document is archived and information here might be outdated. Recommended version. |
ITopologyGraph.Build Method (ArcObjects .NET 10.8 SDK)
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This document is archived and information here might be outdated. Recommended version. |
Creates topo elements from all topology feature classes covering the specified map extent.
[Visual Basic .NET] Public Sub Build ( _ ByVal Extent As IEnvelope, _ ByVal preserveSelection As Boolean _ )
[C#] public void Build ( IEnvelope Extent, bool preserveSelection );
[C++]
HRESULT Build(
IEnvelope* Extent,
VARIANT_BOOL preserveSelection
);
[C++] Parameters Extent
Extent is a parameter of type IEnvelope* preserveSelection
preserveSelection is a parameter of type bool
Use the ITopologyGraph::Build method to construct the Topology Elements (TopologyNodes and TopologyEdges). Once "Build" is performed the Topology Elements are cached in memory and can be used. The elements have to be built before they can be used with other methods.
bool BuildTopoGraph(IGeometry buildGeom, ITopologyGraph topoGraph, bool
keepSelection)
{
if (buildGeom == null || topoGraph == null)
return false;
switch (buildGeom.GeometryType)
{
case esriGeometryType.esriGeometryPolygon:
{
ITopologyGraph4 topoGraph4 = topoGraph as ITopologyGraph4;
topoGraph4.BuildFromPolygon((IPolygon)buildGeom, keepSelection);
return true;
}
case esriGeometryType.esriGeometryEnvelope:
{
topoGraph.Build((IEnvelope)buildGeom, keepSelection);
return true;
}
default:
return false;
}
}
Private Function BuildTopoGraph(ByVal buildGeom As IGeometry, ByVal topoGraph As ITopologyGraph, ByVal keepSelection As Boolean) As Boolean
If buildGeom Is Nothing OrElse topoGraph Is Nothing Then
Return False
End If
Select Case buildGeom.GeometryType
Case esriGeometryType.esriGeometryPolygon
Dim topoGraph4 As ITopologyGraph4 = TryCast(topoGraph, ITopologyGraph4)
topoGraph4.BuildFromPolygon(CType(buildGeom, IPolygon), keepSelection)
Return True
Case esriGeometryType.esriGeometryEnvelope
topoGraph.Build(CType(buildGeom, IEnvelope), keepSelection)
Return True
Case Else
Return False
End Select
End Function