VB.Net/Generics/Generic Tree

Define and use a generic Tree data structure

Imports System
Imports System.Windows.Forms
Imports System.Collections.Generic
Imports System.ruponentModel
Public Class MainClass
   Shared Sub Main()
        Dim family_tree As New Tree(Of Person)
        Dim root As TreeNode(Of Person) = _
            family_tree.MakeRoot(New Person("Root"))
        Dim child1 As TreeNode(Of Person) = _
            root.AddChild(New Person("First Level Node 1"))
        Dim child2 As TreeNode(Of Person) = _
            root.AddChild(New Person("First Level Node 2"))
        child1.AddChild(New Person("Leap 1"))
        child1.AddChild(New Person("Leap 2"))
        child2.AddChild(New Person("Leap 3"))
        child2.AddChild(New Person("Leap 4"))
        " Display the result.
        Console.WriteLine(family_tree.ToString())
   End Sub 
End Class

Public Class Person
    Public Name As String
    Public Sub New(ByVal new_name As String)
        Name = new_name
    End Sub
    Public Overrides Function ToString() As String
        Return Name
    End Function
End Class

Public Class Tree(Of data_type)
    Private m_Root As TreeNode(Of data_type) = Nothing
    <Description("The tree"s root node."), _
     Category("Data")> _
    Public Property Root() As TreeNode(Of data_type)
        Get
            Return m_Root
        End Get
        Set(ByVal value As TreeNode(Of data_type))
            m_Root = value
        End Set
    End Property
    Public Sub Clear()
        m_Root = Nothing
    End Sub
    Public Function MakeRoot(ByVal node_item As data_type) As TreeNode(Of data_type)
        m_Root = New TreeNode(Of data_type)(node_item)
        Return m_Root
    End Function
    Public Overrides Function ToString() As String
        Return m_Root.ToString()
    End Function
End Class
Public Class TreeNode(Of data_type)
    Public NodeObject As data_type
    Public Children As New List(Of TreeNode(Of data_type))
    Public Sub New(ByVal node_object As data_type)
        NodeObject = node_object
    End Sub
    Public Function AddChild(ByVal node_item As data_type) As TreeNode(Of data_type)
        Dim child_node As New TreeNode(Of data_type)(node_item)
        Children.Add(child_node)
        Return child_node
    End Function
    Public Shadows Function ToString(Optional ByVal indent As Integer = 0) As String
        Dim txt As String
        txt = New String(" "c, indent) & NodeObject.ToString & vbCrLf
        For Each child As TreeNode(Of data_type) In Children
            txt &= child.ToString(indent + 2)
        Next child
        Return txt
    End Function
End Class

Generic Tree

Imports System.Collections
Public Class MainClass
   Public Shared Sub Main()
        Dim rootNode, child1 As TreeNode(Of Employee)
        rootNode = New TreeNode(Of Employee)(New Employee(111, "A"))
        child1 = rootNode.AddChild(New Employee(222, "B"))
        rootNode.AddChild(New Employee(333, "C"))
        child1.AddChild(New Employee(444, "D"))
        child1.AddChild(New Employee(555, "E"))
        Console.WriteLine(rootNode)
   End Sub

End Class

Public Class TreeNode(Of T)
    Public Data As T
    Private _childNodes As ArrayList
    Public Sub New(ByVal nodeData As T)
        Me.Data = nodeData
        Me._childNodes = New ArrayList
    End Sub
    Public ReadOnly Property Children() As TreeNode(Of T)()
        Get
            Return Me._childNodes.ToArray()
        End Get
    End Property
    Default Public ReadOnly Property Item(ByVal index As Long) As TreeNode(Of T)
        Get
            Return Me._childNodes(index)
        End Get
    End Property
    Public Function AddChild(ByVal nodeData As T) As TreeNode(Of T)
        Dim newNode As TreeNode(Of T) = New TreeNode(Of T)(nodeData)
        Me._childNodes.Add(newNode)
        Return newNode
    End Function
    Overrides Function ToString() As String
        Return Me.Data.ToString()
    End Function
End Class

Public Class Employee
    Private _id As Integer
    Private _name As String
    Public Sub New(ByVal id As Integer, ByVal name As String)
        Me._id = id
        Me._name = name
    End Sub
    Public Overrides Function ToString() As String
        Return Me._name
    End Function
End Class