Public Class MyComparer
    Implements IComparer
    Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer _
      Implements System.Collections.IComparer.Compare
        Dim vergleich1 As Grafikwerte = CType(x, Grafikwerte)
        Dim vergleich2 As Grafikwerte = CType(y, Grafikwerte)
        Return (CInt(vergleich1.GIW).CompareTo(CInt(vergleich2.GIW)))
    End Function
End Class

GrafikArray.Sort(New MyComparer)

Always change a running system...or you will never learn!