使用MVC4实体框架实现WCF调用方法失败

Question

I have a wcf application in which i have used Entitity Framework and have implemented dbContext for querying the database. When I view the svc file in browser it exposes the operations.

I have interface class like this:

    [ServiceContract]
    public interface IService1
    {
        [OperationContract]
       List<BooksModels> GetBooksList();

        [OperationContract]
        BooksModels GetBook(int id);

    }

I have the implementation in the svc.cs file like this

    public List<BooksModels> GetBooksList()
    {
        MVCEntity en = new MVCEntity();
      return  en.book.ToList();

    }

    public int GetBookId(int id)
    {
        //return db.book.Find(id);
        return 1;
    }

and the BooksModels class is like this

[DataContract]
    public class BooksModels
        {
            [Key]
            [DataMember]
            public int BookId { get; set; }
            [DataMember]
    public string BookName{get;set;}
    }

and have the config file the default one as created when creating wcf service application .

but when i invoke GetBooksList the service from MVC wcf client it gives me the following error:

Failed to invoke the service. Possible causes: The service is offline or inaccessible; the client-side configuration does not match the proxy; the existing proxy is invalid. Refer to the stack trace for more detail. You can try to recover by starting a new proxy, restoring to default configuration, or refreshing the service.

but when i invoke the second method that returns 1.

i examined that when the service uses the dbContext to return data it gives error and is fine when not.

I have gone through various blogs and also the questions in stackoverflow but didn't help. so how can this problem be addressed. Thanks

Answer 1

I think it's a problem of serialization. Make a serialisation test from you're business layer that take List from entity framework and serialize then deserialize it and compare before and after serialization.

Use DataContractSerializer :

DataContractSerializer serialiser = new DataContractSerializer(typeof(List<BooksModels>));
List<BooksModels> expected = business.GetBooksList();
Stream stream = new MemoryStream();
serialiser.WriteObject(stream, expected);
stream.Position = 0;
List<BooksModels> actual = serialiser.ReadObject(stream) as List<BooksModels>;
Assert.IsNotNull(actual);
Assert.AreEqual(expected.Prop1, actual.Prop1);
Assert.AreEqual(expected.Prop2, actual.Prop2);
// ... //

If it doesn't work you probably use proxy in entity framework. turn off proxy :

context.ContextOptions.ProxyCreationEnabled = false;

Answer 2

I had the same problem. Thanks to Brice2Paris, I solved it by turning off the proxy of EF:

context.Configuration.ProxyCreationEnabled = false;