Visual Studio project type for DTOs that should be accessible in Silverlight

Question

What VS project type should I choose so that the data-transfer-objects that I create in it can be accessible in both in my Silverlight project as well as my WCF service project.

(I want to be able to reuse the DTOs that I define in both projects instead of having VS generate a new set in my Silverlight project when I create a web-service reference to the WCF service).

IE, my question is can the project be a Windows class library, or should it be a Silverlight class library (so as to reference it in both my Silverlight project as well as the WCF project).

Answer 1

You've got three main options:

1. Create two class library projects (one targeting Silverlight, the other the .NET Framework), and share the files between them, as I discuss in this article: http://www.silverlightshow.net/items/Building-a-Silverlight-Line-Of-Business-Application-Part-3.aspx

2. Create your class library as a Silverlight class library. Silverlight applications can't reference class libraries that target the full .NET Framework, but applications targeting the full .NET Framework (such as you WCF Service) can (generally) reference class libraries that target the Silverlight runtime.

3. Try out the Portable Library Tools (currently in beta): http://blogs.msdn.com/b/sburke/archive/2011/01/23/3-screen-coding-is-here-portable-library-tools-allow-you-to-target-multiple-net-platforms-with-one-binary.aspx

Have you thought of using RIA Services (or WCF Data Services) instead of a plain WCF service? RIA Services / WCF Data Services handles this problem for you, and adds other great functionality into the mix.

Hope this helps...

Chris Anderson