Binaryworld - GetNodeRelationship - Evaluates the relationship between two treeview' ... [ VB.net -> Controls-TreeView ]

' Returns a value >0 if node1 is a parent (or grandparent) of node2
' Returns a value <0 if node1 is a child (or grandchild) of node2
' in both cases the number reflects the number of levels between the two nodes
' Returns 0 if the two Nodes are the same or if they belong to different
' subtrees

Function GetNodeRelationship(ByVal node1 As TreeNode, ByVal node2 As TreeNode) _
  As Integer
  If node1 Is node2 Then
    ' this is the simplest case
    Return 0
  ElseIf node1.FullPath.Length > node2.FullPath.Length Then
    ' if the two nodes belong to the same subtree,
    ' then node1 is a (grand)child of node2
    If node1.FullPath.IndexOf(node2.FullPath) = 0 Then
      ' do the loop only if the two nodes appear to belong to the same
      ' subtree check that the relationship really exists
      Do Until (node1.Parent Is Nothing)
        node1 = node1.Parent
        GetNodeRelationship = GetNodeRelationship - 1
        If node1 Is node2 Then Exit Function
      Loop
    End If
  Else
    ' if the two nodes belong to the same subtree,
    ' then node1 is a (grand)parent of node2
    If node2.FullPath.IndexOf(node1.FullPath) = 0 Then
      ' do the loop only if the two nodes appear to belong to the same
      ' subtree check that the relationship really exists
      Do Until (node2.Parent Is Nothing)
        node2 = node2.Parent
        GetNodeRelationship = GetNodeRelationship + 1
        If node1 Is node2 Then Exit Function
      Loop
    End If
  End If

  ' Nodes belong to different subtrees
  Return 0
End Function