workflow in XBAP linked with DB via WCF?

now i have wpf hosted (workflow re-hosted designer )in ASP.NET project via .XBAP file ( XAML Brwser APplication ).

I want to integrate my DB with this .XBAP file and that's also via WCF.

i have 2 questions :

1- how do I integrate XBAP with WCF which needs a cs file to work with it? i search alot i knew that is possible but i didnt find the steps.

2- in the beginning i should be in WPF application ( before making the XBAP file ) integrated with DB via somehow like ORM ( Linq ). now I have XBAP which in another project linked with the same DB, but how the file XBAP will understand the costume activities o开发者_如何学Gor anything others objects inside it that is the DB is the same or will see it?

I really need help Thank you