ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Core.Data.Topology Namespace / TopologyGraph Class / GetEdges Method / GetEdges(Feature) Method
The ArcGIS.Core.Data.Feature that spawns a specific set of topological edges.
Example Version

GetEdges(Feature) Method
Gets the set of TopologyEdges corresponding to the feature specified by parentFeature. This method must be called on the MCT. Use QueuedTask.Run.
Syntax

Parameters

parentFeature
The ArcGIS.Core.Data.Feature that spawns a specific set of topological edges.

Return Value

A list of TopologyEdges that correspond to parentFeature.
Exceptions
ExceptionDescription
A geodatabase-related exception has occurred.
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.");
  }
}
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also