Sélectionner tout les éléments d'une ListBox

Private Sub UserForm_Initialize()

    With Sheets("Bdd")
        For i = 2 To .Range("a65536").End(xlUp).Row
            ListBox1.AddItem
            ListBox1.List(ListBox1.ListCount - 1, 0) = .Cells(i, 1) & "," & .Cells(i, 2)
            ListBox1.List(ListBox1.ListCount - 1, 1) = i
        Next i
    End With

End Sub
Private Sub CommandButton1_Click()

    For i = ListBox1.ListCount - 1 To 0 Step -1
        ListBox1.Selected(i) = True
    Next i

End Sub