ArcGIS Pro 3.1 API Reference Guide
ArcGIS.Core.Data.Topology Namespace / TopologyNode Class
Members Example

In This Topic
    TopologyNode Class
    In This Topic
    Represents a topological node within a topology graph.
    Object Model
    TopologyNode ClassGeometry Class
    Syntax
    Example
    Build Map Topology
    private async Task BuildGraphWithActiveView()
    {
      await QueuedTask.Run(() =>
      {
        //Build the map topology graph
        MapView.Active.BuildMapTopologyGraph<TopologyDefinition>(async topologyGraph =>
        {
          //Getting the nodes and edges present in the graph
          var topologyGraphNodes = topologyGraph.GetNodes();
          var topologyGraphEdges = topologyGraph.GetEdges();
    
          foreach (var node in topologyGraphNodes)
          {
            // do something with the node
          }
          foreach (var edge in topologyGraphEdges)
          {
            // do something with the edge
          }
    
          MessageBox.Show($"Number of topo graph nodes are:  {topologyGraphNodes.Count}.\n Number of topo graph edges are {topologyGraphEdges.Count}.", "Map Topology Info");
        });
      });
    }
    ExploreTopologyGraph
    public void ExploreTopologyGraph()
    {
      using (Geodatabase geodatabase = new Geodatabase(new FileGeodatabaseConnectionPath(new Uri(@"C:\TestData\GrandTeton.gdb"))))
      using (Topology topology = geodatabase.OpenDataset<Topology>("Backcountry_Topology"))
      {
        // Build a topology graph using the extent of the topology dataset.
    
        topology.BuildGraph(topology.GetExtent(), (topologyGraph) =>
        {
          using (Feature campsites12 = GetFeature(geodatabase, "Campsites", 12))
          {
            IReadOnlyList<TopologyNode> topologyNodesViaCampsites12 = topologyGraph.GetNodes(campsites12);
    
            TopologyNode topologyNodeViaCampsites12 = topologyNodesViaCampsites12[0];
    
            IReadOnlyList<TopologyEdge> allEdgesConnectedToNodeViaCampsites12 = topologyNodeViaCampsites12.GetEdges();
            IReadOnlyList<TopologyEdge> allEdgesConnectedToNodeViaCampsites12CounterClockwise = topologyNodeViaCampsites12.GetEdges(false);
    
            System.Diagnostics.Debug.Assert(allEdgesConnectedToNodeViaCampsites12.Count == allEdgesConnectedToNodeViaCampsites12CounterClockwise.Count);
    
            foreach (TopologyEdge edgeConnectedToNodeViaCampsites12 in allEdgesConnectedToNodeViaCampsites12)
            {
              TopologyNode fromNode = edgeConnectedToNodeViaCampsites12.GetFromNode();
              TopologyNode toNode = edgeConnectedToNodeViaCampsites12.GetToNode();
    
              bool fromNodeIsTheSameAsTopologyNodeViaCampsites12 = (fromNode == topologyNodeViaCampsites12);
              bool toNodeIsTheSameAsTopologyNodeViaCampsites12 = (toNode == topologyNodeViaCampsites12);
    
              System.Diagnostics.Debug.Assert(fromNodeIsTheSameAsTopologyNodeViaCampsites12 || toNodeIsTheSameAsTopologyNodeViaCampsites12,
                "The FromNode *or* ToNode of each edge connected to 'topologyNodeViaCampsites12' should be the same as 'topologyNodeViaCampsites12' itself.");
    
              IReadOnlyList<FeatureInfo> leftParentFeaturesBoundedByEdge = edgeConnectedToNodeViaCampsites12.GetLeftParentFeatures();
              foreach (FeatureInfo featureInfo in leftParentFeaturesBoundedByEdge)
              {
                System.Diagnostics.Debug.Assert(!String.IsNullOrEmpty(featureInfo.FeatureClassName));
                System.Diagnostics.Debug.Assert(featureInfo.ObjectID > 0);
                EnsureShapeIsNotEmpty(featureInfo);
              }
    
              IReadOnlyList<FeatureInfo> leftParentFeaturesNotBoundedByEdge = edgeConnectedToNodeViaCampsites12.GetLeftParentFeatures(false);
              foreach (FeatureInfo featureInfo in leftParentFeaturesNotBoundedByEdge)
              {
                System.Diagnostics.Debug.Assert(!String.IsNullOrEmpty(featureInfo.FeatureClassName));
                System.Diagnostics.Debug.Assert(featureInfo.ObjectID > 0);
                EnsureShapeIsNotEmpty(featureInfo);
              }
    
              IReadOnlyList<FeatureInfo> rightParentFeaturesBoundedByEdge = edgeConnectedToNodeViaCampsites12.GetRightParentFeatures();
              foreach (FeatureInfo featureInfo in rightParentFeaturesBoundedByEdge)
              {
                System.Diagnostics.Debug.Assert(!String.IsNullOrEmpty(featureInfo.FeatureClassName));
                System.Diagnostics.Debug.Assert(featureInfo.ObjectID > 0);
                EnsureShapeIsNotEmpty(featureInfo);
              }
    
              IReadOnlyList<FeatureInfo> rightParentFeaturesNotBoundedByEdge = edgeConnectedToNodeViaCampsites12.GetRightParentFeatures(false);
              foreach (FeatureInfo featureInfo in rightParentFeaturesNotBoundedByEdge)
              {
                System.Diagnostics.Debug.Assert(!String.IsNullOrEmpty(featureInfo.FeatureClassName));
                System.Diagnostics.Debug.Assert(featureInfo.ObjectID > 0);
                EnsureShapeIsNotEmpty(featureInfo);
              }
            }
          }
        });
      }
    }
    
    private void EnsureShapeIsNotEmpty(FeatureInfo featureInfo)
    {
      using (Feature feature = featureInfo.GetFeature())
      {
        System.Diagnostics.Debug.Assert(!feature.GetShape().IsEmpty, "The feature's shape should not be empty.");
      }
    }
    
    Inheritance Hierarchy

    System.Object
       ArcGIS.Core.CoreObjectsBase
          ArcGIS.Core.Data.Topology.TopologyElement
             ArcGIS.Core.Data.Topology.TopologyNode

    Requirements

    Target Platforms: Windows 11, Windows 10

    ArcGIS Pro version: 3.0 or higher.
    See Also