Error creating RIA Service "...cannot be used as a type parameter..."

Question

I am trying to add a RIA service to my LightSwitch app and am getting an error.  (I am eventually trying to get this to work with stored procedures and UDFs, but right now, I am just trying to get it to work with one table.)

1) I added a class library project called "WCF_RIA".

2) I added an ADO.NET Entity Data Model, selected one table for testing and created the edmx.

3) I added a class file for my domain service called "TPE_Domain_Service"'

I added the following code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.ServiceModel.DomainServices.EntityFramework;
using System.ServiceModel.DomainServices.Server;

namespace WCF_RIA
{
   public class TPE_DomainService : LinqToEntitiesDomainService<tpe1Entities>
   {
   }
}

I am getting this error:

Error 2 The type 'WCF_RIA.tpe1Entities' cannot be used as type parameter 'TContext' in the generic type or method 'System.ServiceModel.DomainServices.EntityFramework.LinqToEntitiesDomainService<TContext>'. There is no implicit reference conversion from 'WCF_RIA.tpe1Entities' to 'System.Data.Objects.ObjectContext'. C:\Users\Mark\Documents\Visual Studio 2013\Projects\PE1\WCF_RIA\TPE_DomainService.cs 13 17 WCF_RIA

Here is the auto-generated code in tpe1.Context.cs:

namespace WCF_RIA
{
    using System;
    using System.Data.Entity;
    using System.Data.Entity.Infrastructure;
    
    public partial class tpe1Entities : DbContext
    {
        public tpe1Entities()
            : base("name=tpe1Entities")
        {
        }
    
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            throw new UnintentionalCodeFirstException();
        }
    
        public DbSet<Clients> Clients { get; set; }
    }
}

I don't know what this error means. Any help would be greatly appreciated.

Thanks,

Mark

Answer 1

Mark,

Your Domain Service is expecting an ObjectContext but your Entities have been generated with DbContext.

You might try to regenerate the Entities using the ObjectContext templates. I have not used LightSwitch but, in VS if you open the Model (.edmx ). Right click on the design surface and add a new code item, choose Entity Framework Object Context.  You might need to remove the DbContext entities file to avoid namespace conflicts.

Brad

Answer 2

You may find this helpful:

Creating a WCF RIA Service for Visual Studio LightSwitch 2013

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