Module Module1

    Sub Main()

        Dim l As New List(Of X)

        ' Aggiungo due nuove istanze
        l.Add(New X(1, "Testo 1"))
        l.Add(New X(2, "Testo 2"))

        ' Visualizzo il loro valore
        For Each z As X In l
            Console.WriteLine(String.Format("A={0}, B={1}", z.A, z.B))
        Next

        ' Modifico il valore
        For Each z As X In l
            z.A += 10
            z.B = "Testo " & z.A.ToString()
        Next

        ' Visualizzo il nuovo valore
        For Each z As X In l
            Console.WriteLine(String.Format("A={0}, B={1}", z.A, z.B))
        Next

        Console.ReadLine()
    End Sub

    Public Class X
        Private _A As Integer
        Private _B As String

        Public Sub New()
        End Sub

        Public Sub New(ByVal myA As Integer, ByVal myB As String)
            Me.A = myA
            Me.B = myB
        End Sub

        Public Property A() As Integer
            Get
                Return _A
            End Get
            Set(ByVal value As Integer)
                _A = value
            End Set
        End Property

        Public Property B() As String
            Get
                Return _B
            End Get
            Set(ByVal value As String)
                _B = value
            End Set
        End Property


    End Class
End Module