Public Class Form1
 
    'Das Interface
    Public Interface IDemo
        Function doSomething(ByVal a As Integer, _
               ByVal b As Integer) As Integer
    End Interface
 
    'Zwei Klassen zur Auswahl
    Public Class Addition
        Implements IDemo
        Private Function doSomething(ByVal a As Integer, _
            ByVal b As Integer) As Integer _
            Implements IDemo.doSomething
 
            Return a + b
        End Function
    End Class
 
    Public Class Subtraktion
        Implements IDemo
        Private Function doSomething(ByVal a As Integer, _
            ByVal b As Integer) As Integer _
            Implements IDemo.doSomething
 
            Return a - b
        End Function
    End Class
 
    'Die Klasse mit der neuen Methode DoIt
    Public Class whatever
 
        Public Property param1 As Integer
        Public Property param2 As Integer
 
        'generischer Parameter mit Interface-Constraint
        Public Function DoIt(Of T As IDemo)(ByVal operation As T) As Integer
            Return operation.doSomething(param1, param2)
        End Function
 
    End Class
 
 
 
    Private Sub Form1_Load(sender As System.Object, _
        e As System.EventArgs) Handles MyBase.Load
 
        'Verwendung
        Dim we As New whatever
        we.param1 = 8
        we.param2 = 15
 
        'Übergabe einer Klasseninstanz an "DoIt"
        Dim result1 As Integer = we.DoIt(New Addition)
        Dim result2 As Integer = we.DoIt(New Subtraktion)
 
    End Sub
End Class