Appendix A. Three Approaches to COM Interop with ADSI

Throughout the book, we have mentioned that it is useful and occasionally even necessary to do some kind of COM interop with ADSI when using System.DirectoryServices (SDS). For example, it is useful for harnessing the IADsNameTranslate interface and it is necessary for setting attributes with the LargeInteger syntax (2.5.5.16, see Chapter 6).

There are actually three different approaches we can use for COM interop:

• The "standard" method, where an interop assembly is generated with tlbimp.exe or by setting a COM reference to activeds.tlb in Visual Studio .NET
• The reflection method, where we use types in the System.Reflection namespace to discover and invoke ADSI COM interface methods dynamically at runtime
• The "roll your own" approach of writing our own .NET declaration for a COM type by hand