Triple order traversal of a binary tree in vb.net

Vb program for Triple order traversal of a binary tree. Here mentioned other language solution.

' Include namespace system
Imports System 
'    Vb.net program for
'    Triple order traversal of a binary tree

'  Binary Tree node
Public Class TreeNode
    Public  data As Integer
    Public  left As TreeNode
    Public  right As TreeNode
    Public Sub New(ByVal data As Integer)
        '  Set node value
        Me.data = data
        Me.left = Nothing
        Me.right = Nothing
    End Sub
End Class
public Class BinaryTree
    Public  root As TreeNode
    Public Sub New()
        '  Set initial tree root
        Me.root = Nothing
    End Sub
    Public Sub tripleOrder(ByVal node As TreeNode)
        if (node IsNot Nothing) Then
            '  Print preorder node
            Console.Write(" " + node.data.ToString())
            '  Visit left subtree
            Me.tripleOrder(node.left)
            '  Print inorder node
            Console.Write(" " + node.data.ToString())
            '  Visit right subtree
            Me.tripleOrder(node.right)
            '  Print postorder node
            Console.Write(" " + node.data.ToString())
        End If
    End Sub
    Public Shared Sub Main(ByVal args As String())
        '  Create new binary trees
        Dim tree As BinaryTree = New BinaryTree()
        '         4    
        '        / \                         
        '       /   \    
        '     -4     7    
        '     / \     \               
        '    2   3     1
        '       / \   / 
        '      6   8 5
        '     /       
        '    9          
        '  ----------------------
        '  Constructing binary tree
        tree.root = New TreeNode(4)
        tree.root.left = New TreeNode(-4)
        tree.root.left.right = New TreeNode(3)
        tree.root.left.right.left = New TreeNode(6)
        tree.root.left.right.left.left = New TreeNode(9)
        tree.root.left.right.right = New TreeNode(8)
        tree.root.left.left = New TreeNode(2)
        tree.root.right = New TreeNode(7)
        tree.root.right.right = New TreeNode(1)
        tree.root.right.right.left = New TreeNode(5)
        '  Print triple order
        '  ----------------------------------
        '  4 -4 2 2 2 -4 3 6 9 9 9 6 6 3 8 8 ..
        '  8 3 -4 4 7 7 1 5 5 5 1 1 7 4
        tree.tripleOrder(tree.root)
    End Sub
End Class

Output

 4 -4 2 2 2 -4 3 6 9 9 9 6 6 3 8 8 8 3 -4 4 7 7 1 5 5 5 1 1 7 4