WebAPI issue while retrieving data from database using Entity Framework

Question

I created a Project to learn about web api and entity framework. Well, when I try to connect my service with the database, the service did not retrieve the data from database. Below is my connection string:

<add name="CotacaoContext" connectionString="Data Source=Minha_Maquina\Instancia; Initial Catalog=Cotacao; User Id=sa; Password=d123" providerName="System.Data.SqlClient" />

This is my controller and the method GetUsuarios. This method(GetUsuarios) retrieves all data from DB(Table=Usuarios).

public class UsuarioController : ApiController
{
    private CotacaoContext contexto = new CotacaoContext("CotacaoContext");

    [AcceptVerbs("Get")]
    public IEnumerable<Usuarios> GetUsuarios()
    {
        return contexto.Usuario.AsEnumerable();
    }

    public Usuarios GetUsuarioById(int id)
    {
        Usuarios usuario = contexto.Usuario.Find(id);
        if(usuario == null)
        {
            throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound));
        }

        return usuario;
    }

    protected override void Dispose(bool disposing)
    {
        contexto.Dispose();
        base.Dispose(disposing);
    }
}

Context class with respective DBSet:

public class CotacaoContext : DbContext
{
    public CotacaoContext()
        : base("name=CotacaoContext")
    {

    }
    public DbSet<Usuarios> Usuario { get; set; }
    public DbSet<Login> Login { get; set; }
}

model class

public class Usuarios
{
    public int Id { get; set; }
    public int Tipo_Usuario { get; set; }
    public string NMUsuario { get; set; }
    public string Senha { get; set; }
}

When I debug this line

return contexto.Usuario.AsEnumerable();

I have this problem:

my table has 6 records and in the image 6 records appear in this format " ? ". What does it mean?

Answer 1

Solved.I needed only a ToList() like this:

return contexto.Usuario.AsEnumerable().ToList();

I saw this answer here