Providing a ReadOnly PropertyDescriptor to an Object

Question

I've setup my class to inherit from ICustomTypeDescriptor

I've also then setup this method for the GetProperties implementation for the inheritance.

Public Class POSTerminal
    Inherits BasePacket
    Implements ICustomTypeDescriptor


Public Function GetProperties(ByVal attributes() As System.Attribute) As System.ComponentModel.PropertyDescriptorCollection Implements System.ComponentModel.ICustomTypeDescriptor.GetProperties
    Dim pdC As PropertyDescriptorCollection
    pdC = TypeDescriptor.GetProperties(Me, True)
    Dim addlist As New List(Of PropertyDescriptor)

    For Each pd As PropertyDescriptor In pdC
        If String.Equals(pd.Name, "Code", StringComparison.OrdinalIgnoreCase) Then
            If Not mIsNew Then
                addlist.Add(New ReadonlyIntegerPropertyDescriptor(pd, mCode))
            Else
                addlist.Add(pd)
            End If
        Else
            addlist.Add(pd)
        End If
    Next

    Return New PropertyDescriptorCollection(addlist.ToArray, True)
End Function

I then have my ReadonlyProperty descriptor class.

it's all working, but I'd just like to check is this the way to do it, or is there a cleaner way?