Public Class Computer
     Public Hersteller as String
     Public Mainboard as String
     ...
 
End Class

Public Class FestplattenCollection
    Inherits System.Collections.CollectionBase
 
    Public Sub Add(hdd as Festplatte)
        MyBase.List.Add(hdd)
    End Sub
 
    Public Sub Remove(hdd as Festplatte)
        MyBase.List.Remove(hdd)
    End Sub
    'Eventuell noch das gleiche für "Contains" oder anderen Methoden
 
    Public Property Item(i as Integer) as Festplatte
        Get
            Item=CType(base.Item(i), Festplatte)
        End Get
        Set(value as Festplatte)
            base.Item(i)=value
        End Set
    End Property
End Class

Public Class Computer
     Public Hersteller as String
     Public Mainboard as String
     ...
     Public Festplatten as FestplattenCollection
End Class

Public Class Festplatte
    Implements Hardware
    'Hier müssten alle zusätzlichen Eigenschaften hin, die nicht in der 
    ' Basisklasse sind
End Class

Public Class HardwareCollection
    Inherits System.Collections.CollectionBase
 
    Public Sub Add(h as Hardware)
        MyBase.List.Add(h)
    End Sub
 
    Public Sub Remove(h as Hardware)
        MyBase.List.Remove(h)
    End Sub
    'Eventuell noch das gleiche für "Contains" oder anderen Methoden
 
    Public Property Item(i as Integer) as Hardware
        Get
            Item=CType(base.Item(i), Hardware)
        End Get
        Set(value as Hardware)
            base.Item(i)=value
        End Set
    End Property
End Class

Dim MeinPC as Computer
....
For Each hdd as Festplatte in MeinPC.Komponenten
    Debug.Write(hdd.Hersteller)
Next