How to use collection with entity framework 3.5 in n-tier application?

Question

I'm starting new project with EF 3.5 (Visual Studio 2008 SP1, .NET Framework 3.5 SP1) It's N-Tier application, one important aspect of this project is return collection of datums which I prefer to use IEnumerable. I also use EntityBag in this project and I found some problem.

1. I can return collection from AppServer but I can't track any change to my entity.
2. After I've stuck with 1. then I try to use EntityBag but it seem has some problem when working with collection.

From 1. and 2. I've no idea which ways to continue, Is it has another ways to working in N-Tier environment with IEnumerable data?

Thanks.

Answer 1

Just a thought concerning 1.
Have you tried to work with IEnumerable and then attach these entities to the context again (Something like a Save method putting these entities back to the DAL and processing them there)?
In fact, this should give you the change tracking you wish.