[vb.net] Programmation "cascade"

Public Class Form1
    'Crée la collection d'objet
    Dim ClGroup As New Microsoft.VisualBasic.Collection()
    Dim txtB() As String
    Dim Résultat(3) As String
    Dim Num As Byte = 0

    Sub ChangeBouton()
        Dim E As Byte = Num * 3
        For i As Byte = 0 To 2
            ClGroup(CStr(i + 1)).text() = txtB(E + i)
            ClGroup(CStr(i + 1)).visible = Not txtB(E + i) = ""
        Next
        ClGroup("4").Visible = Num > 0
        Label1.Text = ""
    End Sub
    Private Sub AllButton_MouseDown(ByVal sender As System.Object, ByVal e As System.EventArgs)
        If sender.tag = 4 Then
            Num -= 1
            ChangeBouton()
        Else
            Résultat(Num) = sender.text
            Num += 1
            If Num < 3 Then
                ChangeBouton()
            Else
                Dim S As String = "Sélection = "
                For i = 0 To 2 : S = S & Résultat(i) & " | " : Next
                Label1.Text = S
            End If
        End If
    End Sub
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        txtB = {"Jean", "Michel", "Paul", _
                  "Homme", "Femme", "", _
                 "Jeune", "Adulte", "Vieux"}
        For i As Byte = 1 To 4
            Dim Bout As New Button
            With Bout
                If i = 4 Then
                    .Location = New Point(180, 147)
                    .Text = "Précédant"
                Else
                    .Location = New Point((i - 1) * 90 + 9, 113)
                End If
                .Size = New Size(75, 23)
                .Tag = i
                AddHandler .MouseDown, AddressOf AllButton_MouseDown
                ClGroup.Add(Bout, .Tag)
            End With
            Controls.Add(Bout)
        Next i
        ChangeBouton()
    End Sub

End Class