Assign Geometric Network connectivity using ArcObjects

Esri_SpainDeveloper_Group

Hi,

Somebody knows if it's possible to assign using an ArcObjects method the connectivy between  edges and nodes?

We have two FC Junctions and Edges.

Feature Class Junctions

OBJECTID JUNCTIONID TYPE    NAME....
1           J1      TYPEI   NODE1
2           J2      TYPEII  NODE2
3           J3      TYPEI   NODE3
...         ...     ...
...         ...     ...

Feature Class Edges

OBJECTID EDGEID  JUNCTIONFROM JUNCTIONTO
1        EDGE1         J1          J5
2        EDGE2         J2          J7
3        EDGE3         J1          J8
4        EDGE4         J2          J9

We want to establish connectivity via ArcObjects, reading the connectivity rules between edges and junctions from Fields JUNCTIONFROM, JUNCTIONTO that are in Edges Feature Class, using an ArcObjects method.

The spatial relationships between entities is like that of the image [ATTACH=CONFIG]21742[/ATTACH]

Any help could be great for us!!

Thank you

Network.jpg

Hornbydd

Hello,

About a year ago I played around with MapTopology to see what one could do with it. The code below is in VBA and shows you how you could identify dangling nodes. The limitation of this method is that it works only when you are in edit mode.


Duncan

Public Sub SelectDanglingPolylines()
 ' Description: Takes a polyline dataset and select all dangling polylines.
 '
 ' Requirements: You need to be in edit mode and have added the layer to a MAP TOPOLOGY,
 ' also polyline layer must be first in TOC.
 '
 ' Limitations: Large datasets take a long time to build the cache and may even fail.
 '
 ' Author: Duncan Hornby
 ' Created: 11/12/2011
 '
 
 ' Get map and then first layer, must be of polyline type
 Dim pMXDocument As IMxDocument
 Set pMXDocument = ThisDocument
 Dim pMap As IMap
 Set pMap = pMXDocument.FocusMap
 Dim pLayer As ILayer
 Set pLayer = pMap.Layer(0)
 Dim pFeatureLayer As IFeatureLayer
 Set pFeatureLayer = pLayer
 Dim pFeatureClass As IFeatureClass
 Set pFeatureClass = pFeatureLayer.FeatureClass
 If pFeatureClass.ShapeType <> esriGeometryPolyline Then
 MsgBox "This code works only with polylines!", vbExclamation, "Wrong data type at layer 0"
 Exit Sub
 End If
 
 ' Get editor and topology extension
 Dim pEditor As IEditor
 Dim pID As New UID
 Dim pTopologyExtension As ITopologyExtension
 Dim pTEID As New UID
 pID = "esriEditor.editor"
 Set pEditor = Application.FindExtensionByCLSID(pID)
 pTEID = "esriEditorExt.TopologyExtension"
 Set pTopologyExtension = Application.FindExtensionByCLSID(pTEID)
 If pTopologyExtension.CurrentTopology Is Nothing Then Exit Sub
 
 ' Get a MAP topology not a geodatabase topology
 Dim pMapTopology As IMapTopology
 If TypeOf pTopologyExtension.CurrentTopology Is IMapTopology Then
 Set pMapTopology = pTopologyExtension.MapTopology
 Else
 ' Not a Map Topology
 Exit Sub
 End If
 
 ' This is the colection that FID are added to
 Dim aColl As New Collection
 
 ' Build cache
 Application.StatusBar.Message(0) = "Building MAP TOPOLOGY cache, this can take a long time on large datasets..."
 DoEvents
 Dim pGeoDataset As IGeoDataset
 Set pGeoDataset = pFeatureClass
 Dim pEnvelope As IEnvelope
 Set pEnvelope = pGeoDataset.Extent
 pMapTopology.Cache.Build pEnvelope, False
 
 ' Identify dangling nodes and add polyline FID to collection
 Application.StatusBar.Message(0) = "Identifying dangling nodes..."
 DoEvents
 Dim pEnumTopologyParent As IEnumTopologyParent
 Dim pTopologyNode As ITopologyNode
 Dim pEnumTopologyNode As IEnumTopologyNode
 Set pEnumTopologyNode = pMapTopology.Cache.Nodes
 pEnumTopologyNode.Reset
 Set pTopologyNode = pEnumTopologyNode.Next
 While Not pTopologyNode Is Nothing
 If pTopologyNode.Degree = 1 Then
 ' As this has 1 degree it has only 1 parent polyline
 Set pEnumTopologyParent = pTopologyNode.Parents
 pEnumTopologyParent.Reset
 aColl.Add (pEnumTopologyParent.Next.m_FID) 'Adds polyline FID to collection
 End If
 Set pTopologyNode = pEnumTopologyNode.Next
 Wend
 
 ' Use collection to select polylines
 Application.StatusBar.Message(0) = "Selecting polylines..."
 DoEvents
 Dim pFeatureSelection As IFeatureSelection
 Set pFeatureSelection = pFeatureLayer
 Dim X As Variant
 For Each X In aColl
 pFeatureSelection.SelectionSet.Add CLng(X)
 Next
 pMXDocument.ActiveView.PartialRefresh esriViewGeoSelection, Nothing, pEnvelope
 Application.StatusBar.Message(0) = ""
 DoEvents
End Sub