title: DomainService only works with EDMX file?
body: <p>I want to add a new domain service class within vs2010. I choose my entity framework database context in the dialog "Add New Domain Service Class", but it doesen't show me the available entities. If I click "ok" VS2010 gives me the following error message:</p>
  
  <pre><code>---------------------------
  Microsoft Visual Studio
  ---------------------------
  Value cannot be null.
  
  Parameter name: ssdlPath
  ---------------------------
  OK   
  ---------------------------
  </code></pre>
  
  <p>The reason for this is, that I don't have an EDMX file (I tried it with an EDMX file and it worked). Instead I have a seperate csdl, msl and ssdl file. This is because I want to support multiple databases.</p>
  
  <p>How can I use the class LinqToEntitiesDomainService with my data context? The entity objects and the data context are generated with the POCO template. If I add the Domain Serive class manually (not using the domain service wizzard) I get a compile time error which says basically the same:</p>
  
  <pre><code>MSBuild\Microsoft\Silverlight\v4.0\Microsoft.Ria.Client.targets(303,5): error : Value cannot be null.
  MSBuild\Microsoft\Silverlight\v4.0\Microsoft.Ria.Client.targets(303,5): error : Parameter name: ssdlPath
  </code></pre>
  
  <p>Can anyone help?</p>