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($"\t{parentFeature.FeatureClassName}; OID: {parentFeature.ObjectID}");
}
TopologyNode topologyNodeViaCampsites12 = topologyGraph.FindClosestElement <TopologyNode>(queryPointViaCampsites12, searchRadius);
if (topologyNodeViaCampsites12 != null)
{
// There exists a TopologyNode nearest to the query point within searchRadius units.
}
TopologyEdge topologyEdgeViaCampsites12 = topologyGraph.FindClosestElement <TopologyEdge>(queryPointViaCampsites12, searchRadius);
if (topologyEdgeViaCampsites12 != null)
{
// There exists a TopologyEdge nearest to the query point within searchRadius units.
}
});
}
}
private static void ExploreTopologyGraph(Geodatabase geodatabase, Topology topology)
{
// Build a topology graph using the extent of the topology dataset.
topology.BuildGraph(topology.GetExtent(), (topologyGraph) =>
{
// To visualize where the query point is, see "QueryPoint.PNG" in the "..\Data" folder.
Feature featureViaTrailPoints66 = GetFeature(geodatabase, "Trail_Points", 66);
try
{
MapPoint queryPointViaTrailPoints66 = featureViaTrailPoints66.GetShape() as MapPoint;
double searchRadius = 1.0;
TopologyNode topologyNodeViaTrailPoints66 = topologyGraph.FindClosestElement <TopologyNode>(queryPointViaTrailPoints66, searchRadius);
System.Diagnostics.Debug.Assert(topologyNodeViaTrailPoints66 != null, "There should be a topology node corresponding to 'queryPointViaTrailPoints66' within the 'searchRadius' units.");
IReadOnlyList <FeatureInfo> parentFeatures = topologyNodeViaTrailPoints66.GetParentFeatures();
Console.WriteLine("***************************************************************************");
Console.WriteLine("The parent features that spawn 'topologyNodeViaTrailPoints66' are:");
foreach (FeatureInfo parentFeature in parentFeatures)
{
Console.WriteLine($"\t{parentFeature.FeatureClassName}; OID: {parentFeature.ObjectID}");
}
IReadOnlyList <TopologyEdge> allEdgesConnectedToNodeViaTrailPoints66 = topologyNodeViaTrailPoints66.GetEdges();
foreach (TopologyEdge edge in allEdgesConnectedToNodeViaTrailPoints66)
{
IReadOnlyList <FeatureInfo> parents = edge.GetParentFeatures();
System.Diagnostics.Debug.Assert(parents.Count == 1, "The edge should have only 1 corresponding parent feature.");
FeatureInfo parentFeature = parents[0];
// To determine whether the edge's "from node" is coincident with "topologyNodeViaTrailPoints66".
bool fromNodeIsCoincidentWithNodeViaTrailPoints66 = edge.GetFromNode() == topologyNodeViaTrailPoints66;
// To determine whether the edge's "to node" is coincident with "topologyNodeViaTrailPoints66".
bool toNodeIsCoincidentWithNodeViaTrailPoints66 = edge.GetToNode() == topologyNodeViaTrailPoints66;
if (fromNodeIsCoincidentWithNodeViaTrailPoints66)
{
Console.WriteLine($"The [{parentFeature.FeatureClassName},{parentFeature.ObjectID}] edge's FromNode is coincident with 'topologyNodeViaTrailPoints66'.");
}
if (toNodeIsCoincidentWithNodeViaTrailPoints66)
{
Console.WriteLine($"The [{parentFeature.FeatureClassName},{parentFeature.ObjectID}] edge's ToNode is coincident with 'topologyNodeViaTrailPoints66'.");
}
// Get only polygon features lying to the left of this edge if available (specified by the "boundedByEdge" optional argument).
IReadOnlyList <FeatureInfo> leftParentFeatures = edge.GetLeftParentFeatures();
if (leftParentFeatures.Count == 0)
{
// There are no polygon features lying to the left of this edge; get the set of polygon features that cover this edge.
Console.WriteLine("The set of polygon features that cover this edge:");
leftParentFeatures = edge.GetLeftParentFeatures(false);
}
else
{
Console.WriteLine("The set of polygon features lying to the left of this edge (i.e., left parent polygon features bounded by this edge):");
}
foreach (FeatureInfo leftParentFeature in leftParentFeatures)
{
Console.WriteLine($"\t{leftParentFeature.FeatureClassName}; OID: {leftParentFeature.ObjectID}");
// To get additional information from the parent feature (e.g., shape, globalID), use leftParentFeature.GetFeature().
}
// Get only polygon features lying to the right of this edge if available (specified by the "boundedByEdge" optional argument).
IReadOnlyList <FeatureInfo> rightParentFeatures = edge.GetRightParentFeatures();
if (rightParentFeatures.Count != 0)
{
Console.WriteLine("The set of polygon features lying to the right of this edge (i.e., right parent polygon features bounded by this edge):");
foreach (FeatureInfo rightParentFeature in rightParentFeatures)
{
Console.WriteLine($"\t{rightParentFeature.FeatureClassName}; OID: {rightParentFeature.ObjectID}");
}
}
}
}
finally
{
if (featureViaTrailPoints66 != null)
{
featureViaTrailPoints66.Dispose();
}
}
});
}
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);
}
}
}
});
}
}
