Table: TreeViewData
--------------------------
- id			int			4	
- parentid	int			4	
- caption	 char		255

id	parentid	caption
--------------------------
1	0			Root                                                                                                                                                                                                                                                           
2	1			Item1                                                                                                                                                                                                                                                          
3	1			Item2                                                                                                                                                                                                                                                          
4	2			SubItem1

Option Explicit On
Option Strict On
 
Imports System.Data
 
Public Partial Class MainForm
 
	Dim cnStr As String = "Persist Security Info=False;User ID=<USERID>;Initial" & _
  "Catalog=<DATABASENAME>"
 
	Public Sub New()
		' The Me.InitializeComponent call is required for Windows Forms designer 
' support.
		Me.InitializeComponent()
 
		'
		' TODO : Add constructor code after InitializeComponents
		'
	End Sub
 
	Sub Button1Click(ByVal sender As Object, ByVal e As EventArgs)
		Me.TreeView1.BeginUpdate()
		Dim dt As DataTable = New DataTable("TreeViewData")
        Me.FillDataTable(dt)
        Me.FillTreeView(dt)
        Me.TreeView1.ExpandAll()
        Me.TreeView1.EndUpdate()
	End Sub
 
	Public Sub FillDataTable(ByRef dt As DataTable)
        Try
            Dim sql As String = "SELECT id, parentid, caption FROM TreeViewData" & _
              "ORDER BY ID ASC"
            Dim cn As Data.SqlClient.SqlConnection = New _
            Data.SqlClient.SqlConnection(cnStr)
            Dim da As Data.SqlClient.SqlDataAdapter = New _
            Data.SqlClient.SqlDataAdapter(sql, cn)
            da.Fill(dt)
        Catch ex As Data.SqlClient.SqlException
            MessageBox.Show(ex.Message)
        End Try
    End Sub
 
    Public Sub FillTreeView(ByVal dt As DataTable)
        Dim parentId, id As Integer 
        Dim tn As TreeNode = Nothing 
        For Each dr As DataRow In dt.Rows
            tn = New TreeNode(dr("caption").ToString())
            parentId = CInt(dr("parentid"))
            id = CInt(dr("id"))
            If parentId = 0 Then
                Me.TreeView1.Nodes.Add(tn)
            End If
            FillSubTreeNode(tn, dt, id)
        Next
 
    End Sub
 
    Public Sub FillSubTreeNode(ByRef tn As TreeNode, ByRef dt As DataTable, _
      ByVal id As Integer)
        Dim foundRows() As DataRow = dt.Select("parentid = " + id.ToString(), _
        "id")
        Dim tnSub As TreeNode = Nothing
        dim currentId as Integer = 0
        For Each dr As DataRow In foundRows
            tnSub = New TreeNode((dr("caption").ToString))
            currentId = CInt(dr("id"))
            tn.Nodes.Add(tnSub)
            FillSubTreeNode(tnSub, dt, currentId)
        Next
    End Sub
 
End Class