Public Class Form1
 
	Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles MyBase.Load
		Debug.WriteLine(Test(Of Test1).func(New Test1()))
 
		Debug.WriteLine(Test(Of Test2).func(New Test2()))
	End Sub
End Class
 
Public Class Test1 : Implements ITest1
 
End Class
 
Public Class Test2 : Implements ITest2
 
End Class
 
 
Public Interface ITest1
 
End Interface
 
Public Interface ITest2
 
End Interface
 
Public Class Test(Of T)
	Public Shared Function func(ByVal objekt As T) As String
		If TypeOf objekt Is ITest1 Then	' Bedingung zum überprüfen ist mir unbekannt
			Return "Test1"
		ElseIf TypeOf objekt Is ITest2 Then
			Return "Test2"
		Else
			Return String.Empty
		End If
	End Function
End Class