Public Class Form1
    Dim y As New clsA
    Dim z As New clsA
    Dim a As Integer
    Dim b As Integer
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As  _
      System.EventArgs) Handles MyBase.Load
        AddHandler y.NewValue, AddressOf PopupMessage
        AddHandler z.NewValue, AddressOf PopupMessage
        y.x = 4
        z = y
 
 
        z.x = 9
        MessageBox.Show(y.x.ToString)       ' Ergebnis 9
        MessageBox.Show(z.x.ToString)       ' Ergebnis 9
        y.x = 1
        MessageBox.Show(y.x.ToString)       ' Ergebnis 1
        MessageBox.Show(z.x.ToString)       ' Ergebnis 1
        '  a = 1
        ' b = 2
        'MessageBox.Show(a.ToString)         ' Ergebnis 1
        'MessageBox.Show(b.ToString)         ' Ergebnis 2
        'a = b
        'MessageBox.Show(a.ToString)         ' Ergebnis 2
        'MessageBox.Show(b.ToString)         ' Ergebnis 2
        'b = 3
        'MessageBox.Show(a.ToString)         ' Ergebnis 2
        'MessageBox.Show(b.ToString)         ' Ergebnis 3
        z = y.Clone()
        z.x = 8
        MessageBox.Show(y.x.ToString)       ' Ergebnis 1
        MessageBox.Show(z.x.ToString)       ' Ergebnis 1
    End Sub
 
    Private Sub PopupMessage()
        ' MessageBox.Show("neuer Wert")
    End Sub
End Class
 
 
Class clsA
    Dim pX As Integer
 
    Property x() As Integer
        Get
            Return pX
        End Get
        Set(ByVal value As Integer)
            pX = value
            RaiseEvent NewValue()
        End Set
    End Property
    Public Function Clone()
        Return (Me.MemberwiseClone())
    End Function
    Event NewValue()
End Class