Question

What is the best method/technology to sharing the same data access layer between WPF, Silverlight, and ASP.NET?

I am using ADO.NET Entity framework, and was thinking of a creating a DAL using the Repository pattern.Then using the RIA Services as a dummy middle man to connect Silverlight and ASP.NET. Is this a solid plan or are there other better solutions out there?

Answer 1

One of the solutions I like to use is the following :
– Have a project storing only the entities (for example : Player, Game, Entity) with no reference to the database at all.
– Have a project implementing the repository pattern (Repository, Repository etc…)
– Use ADO.NET Entity Framework code first approach to map with the database (it creates a dynamic child object of your entities contain in your project, see ScottGu’s blog for an explanation on how to use it)

Connecting Silverlight to your pattern can be done with Ria Services or classic WCF services. Usually I try to use WCF whenever possible as Ria Services is not really compliant with an MVVM development.

If you want to use WCF and share your DAL entities with Silverlight you can create a MyDal.Silverlight Silverlight class library project and add symbolic link instead of copies of every entities you will want to share with Silverlight. Then when you’ll add a service reference with visual studio it will be smart enough to not create copies off Player, Game and User to you Silverlight project.

If you want to use Ria Services it will create copies of you entities anyway.

Hope that helps

John