TreeListOperation.NeedsVisitChildren Method

public class TreeListCustomCountOperation : TreeListOperation {
   private int count;

   public TreeListCustomCountOperation() {
      count = 0;
   }
   // the parent node's Location field must contain the Monterey value 
   public override bool NeedsVisitChildren(TreeListNode node) {
      return node["Location"].ToString() == "Monterey";
   }
   // only parent nodes must be visited 
   public override bool NeedsFullIteration {
      get { return false; }
   }
   public override void Execute(TreeListNode node) {
      count += node.Nodes.Count;
   }
   public int Count {
      get { return count; }
   }
}

//... 
// performing the operation and storing its result 
TreeListCustomCountOperation operation = new TreeListCustomCountOperation();
treeList1.NodesIterator.DoOperation(operation);
int result = operation.Count;

Public Class TreeListCustomCountOperation
   Inherits TreeListOperation

   Private _count As Integer 

   Public Sub New()
      _count = 0
   End Sub 

   ' the parent node's Location field must contain the Monterey value 
   Public Overrides Function NeedsVisitChildren(ByVal node As TreeListNode) As Boolean 
      Return node("Location").ToString() = "Monterey" 
   End Function 

   ' only parent nodes must be visited 
   Public Overrides ReadOnly Property NeedsFullIteration() As Boolean 
      Get 
         Return False 
      End Get 
   End Property 

   Public Overrides Sub Execute(ByVal node As TreeListNode)
      _count += node.Nodes.Count
   End Sub 

   Public ReadOnly Property Count() As Integer 
      Get 
         Return _count
      End Get 
   End Property 
End Class 

'... 
' performing the operation and storing its result 
Dim Operation As New TreeListCustomCountOperation()
TreeList1.NodesIterator.DoOperation(Operation)
Dim Result As Integer = Operation.Count