Assembly: System.Xaml (in System.Xaml.dll)
The value for name is expected to be unqualified. Type-qualified names that indicate an attached member should be submitted to GetAttachableMember instead. Prefixed member names should not be used; a prefix is situational to a usage and the XAML type system cannot know the context of such a usage and how the prefix is mapped.
LookupMember is virtual, and therefore, can be overridden. The override has the potential (whether for malicious purposes or otherwise) to change the reported members of a XAML type so that they no longer align in an expected way with the TypeDescriptor Get* information about the underlying CLR type. For any security-critical checks of member reporting, use the underlying CLR type instead.