public void FindClosestElement()
{
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) =>
{
MapPoint queryPointViaCampsites12 = null;
using (Feature campsites12 = GetFeature(geodatabase, "Campsites", 12))
{
queryPointViaCampsites12 = campsites12.GetShape() as MapPoint;
}
double searchRadius = 1.0;
TopologyElement topologyElementViaCampsites12 =
topologyGraph.FindClosestElement<TopologyElement>(
queryPointViaCampsites12, searchRadius);
System.Diagnostics.Debug.Assert(
topologyElementViaCampsites12 != null, "There should be a topology element corresponding to 'queryPointViaCampsites12' within the 'searchRadius' units.");
IReadOnlyList<FeatureInfo> parentFeatures = topologyElementViaCampsites12.GetParentFeatures();
Console.WriteLine("The parent features that spawn 'topologyElementViaCampsites12' are:");
foreach (FeatureInfo parentFeature in parentFeatures)
{
Console.WriteLine($"\t{parentFeature.FeatureClassName}; OID: {parentFeature.ObjectID}");
}
TopologyNode topologyNodeViaCampsites12 = topologyGraph.FindClosestElement<TopologyNode>(queryPointViaCampsites12, searchRadius);
if (topologyNodeViaCampsites12 != null)
{
// There exists a TopologyNode nearest to the query point within searchRadius units.
}
TopologyEdge topologyEdgeViaCampsites12 = topologyGraph.FindClosestElement<TopologyEdge>(queryPointViaCampsites12, searchRadius);
if (topologyEdgeViaCampsites12 != null)
{
// There exists a TopologyEdge nearest to the query point within searchRadius units.
}
});
}
}