Are there any design patterns used in the .NET Framework?

Question

I would like to know: are any GoF design patterns are used in the .NET Framework?

BOUNTY:

I have seen the MSDN link below in an answer. Are

Answer 1

Yes there are many design patterns used in .Net framework BCL. In fact this is the best Place to look at to learn the design pattern's usage in real term perspective.

Pattern : Implementation

Observer Pattern : Implemented as Events & Delegates

Decorator Pattern: Implemented in System.IO Stream classes

Iterator Pattern : IEnumerable & Iterator

Strategy Pattern : Implemented in Linq thru Lambda experssion queries (list.Where(expression))

Factory Pattern : In System.Net.WebRequest

Adapter Pattern : TLB Import / RCW (Runtime Calleable wrappers)

Please check out this video for detailed presentation on this topic.

https://www.youtube.com/watch?v=riHGGYHVoaQ&list=PL2_Cl8E2bG36PGuBGesHFPVM1s6M02JmN