Me.TreeView1.BeginUpdate()
        Me.TreeView1.Nodes.Clear()
inizio ciclo......
            Dim NewNode As New System.Windows.Forms.TreeNode
            Dim NewChildNode As New System.Windows.Forms.TreeNode
            Try
                If SchedinePSColl.Item(i).IdComponente = 1 Then
                    NewNode.ImageIndex = 0
                    NewNode.Text = datodb
                Else
                    NewNode.ImageIndex = 1
                    NewChildNode.Text =  datodb
                End If
                Me.TreeView1.Nodes.Add(NewNode)
            Catch ex As Exception
                MessageBox.Show("Errore nel caricamento dell'elenco clienti" & Chr(10) & ex.Message, "Send.Net", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
                End
            End Try
fine ciclo.....
        Me.TreeView1.ExpandAll()
        Me.TreeView1.EndUpdate()