Dim rndm As New Random
 
   Private Function GetUniqueIntegers(ByVal count As Integer, _
                    ByVal min As Integer, ByVal max As Integer) As Integer()
 
        If max - min + 1 < count Then Return Nothing
 
        'Erstellung einer sortierten Folge von Zufallszahlen ohne Wiederholung
 
        'Zahlenliste erstellen
        Dim lst As New Collections.Generic.List(Of Integer)
        For i As Integer = min To max : lst.Add(i) : Next i
 
        'Ziehung durchführen 
        Dim numbers(count - 1) As Integer, index As Integer
        For i As Integer = 0 To count - 1
            index = rndm.Next(0, lst.Count)
            numbers(i) = lst(index)
            lst.RemoveAt(index)
        Next i
 
        'Sortieren
        Array.Sort(numbers)
 
        Return numbers
    End Function

Dim lottozahlen() As Integer = GetUniqueIntegers(6, 1, 49)