Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load

        If Not Page.IsPostBack Then

            PopulateTreeView()
        End If

    End Sub

    Private Sub PopulateTreeView()

        Dim treeViewData As DataTable = GetTreeViewData()
        AddTopTreeViewNodes(treeViewData)

    End Sub

    Private Function GetTreeViewData() As DataTable

        ' Get Menu table            
        Dim selectCommand As String = "SELECT ID_categorie, parent_categoria, nome_categoria FROM tab_categorie"
        Dim conString As String = ConfigurationManager.ConnectionStrings("connessione").ConnectionString
        Dim dad As New SqlDataAdapter(selectCommand, conString)
        Dim dtblDiscuss As New DataTable()
        dad.Fill(dtblDiscuss)
        Return dtblDiscuss


    End Function


    Private Sub AddTopTreeViewNodes(treeViewData As DataTable)

        Try
            Dim view As New DataView(treeViewData)
            view.RowFilter = "[parent_categoria] = 0"
            For Each row As DataRowView In view

                Dim MI As MenuItem = New MenuItem("<img src='/images/bullet.png' border='0' align=''absmiddle /><a href='/" + ElencoVariabili.Categorie + "/" & LCase(ElencoFunzioni.CReplaceNome(row("nome_categoria"))) & "-" & row("ID_categorie") & ".aspx'>" & row("nome_categoria").ToString() & "</a>", row("ID_categorie").ToString())
                'Dim newNode As New TreeNode(row("Description").ToString(), row("Id").ToString())

                Menu1.Items.Add(MI)

                'TreeView1.Nodes.Add(newNode)

                AddChildTreeViewNodes(treeViewData, MI)
            Next

        Catch ex As Exception
            ScriptManager.RegisterStartupScript(Page, GetType(Page), "dialog", "alert('Unexpected Error');", True)
        End Try


    End Sub

    'Add child Nodes for the menu

    Private Sub AddChildTreeViewNodes(treeViewData As DataTable, parentTreeViewNode As MenuItem)

        Try

            Dim view As New DataView(treeViewData)
            view.RowFilter = "[parent_categoria]=" + parentTreeViewNode.Value
            For Each row As DataRowView In view

                Dim MI As MenuItem = New MenuItem(row("nome_categoria").ToString(), row("ID_categorie").ToString())

                'Dim newNode As New TreeNode(row("Description").ToString(), row("Id").ToString())

                parentTreeViewNode.ChildItems.Add(MI)
                AddChildTreeViewNodes(treeViewData, MI)
            Next


        Catch ex As Exception
            ScriptManager.RegisterStartupScript(Page, GetType(Page), "dialog", "alert('Unexpected Error');", True)

        End Try

    End Sub