MVC3 + Ninject + Entity framework 4 - entity-framework

Question

i have this Dependency resolver
public class NinjectDependencyResolvercs : IDependencyResolver
{
private readonly IResolutionRoot resolutionRoot;
public NinjectDependencyResolvercs(IResolutionRoot kernel)
{
resolutionRoot = kernel;
}
public object GetService(Type serviceType)
{
return resolutionRoot.TryGet(serviceType);
}
public IEnumerable<object> GetServices(Type serviceType)
{
return resolutionRoot.GetAll(serviceType);
}
}
in global.asax.cs
// Ninject DI container ----------------------------------------------------------- |
public void SetupDependencyInjection()
{
// Create Ninject DI kernel
IKernel kernel = new StandardKernel();
#region Register services with Ninject DI Container
// DbContext to SqlDataContext
kernel.Bind<DbContext>()
.To<SqlDataContext>();
// IRepository to SqlRepository
kernel.Bind<IRepository>()
.To<SqlRepository>();
// IUsersServices to UsersServices
kernel.Bind<IUsersServices>()
.To<UsersServices>();
// IMessagesServices to MessagesServices
kernel.Bind<IMessagesServices>()
.To<MessagesServices>();
// IJobAdvertsServices to JobAdvertsServices
kernel.Bind<IJobAdvertsServices>()
.To<JobAdvertsServices>();
#endregion
// Tell ASP.NET MVC 3 to use Ninject DI Container
DependencyResolver.SetResolver(new NinjectDependencyResolvercs(kernel));
}
// --------------------------------------------------------------------------------- |
and class
public class SqlDataContext : DbContext
{
public DbSet<User> Users { get; set; }
public DbSet<Profile> Profiles { get; set; }
public DbSet<Role> Roles { get; set; }
public DbSet<JobAdvert> JobAdverts { get; set; }
public DbSet<Message> Messages { get; set; }
protected override void OnModelCreating(System.Data.Entity.ModelConfiguration.ModelBuilder modelBuilder)
{
modelBuilder.Entity<User>().HasMany(x => x.Roles).WithMany(x => x.Users).Map(x =>
{
x.MapLeftKey(y => y.UserId, "UserId");
x.MapRightKey(y => y.RoleId, "RoleId");
x.ToTable("UsersInRoles");
});
base.OnModelCreating(modelBuilder);
}
}
all dependecies work fine but for DbContext to SqlDataContext is problem. If use this:
public class SqlRepository
{
private DbContext dataContext;
public SqlRepository(DbContext dataContext) {
this.dataContext = dataContext;
}
public DbSet<User> Users {
get {
return dataContext.Users;
}
}
}
then
dataContext.Users
and all others properties alert this error:
'System.Data.Entity.DbContext' does not contain a definition for 'JobAdverts' and no extension method 'JobAdverts' accepting a first argument of type 'System.Data.Entity.DbContext' could be found (are you missing a using directive or an assembly reference?)
Have anyone any idea why DI doent work for Class DbContext ?

Answer 1

If I understand correctly, You're injecting DbContext which doesn't have those methods/properties, as they're declared in the derived type SqlDataContext.
You need to inject the SqlDataContext. If you want to use an interface, you'll need to extract an interface from SqlDataContext.
EDIT:
Ninject binds at runtime while the errors you're getting (I presume) are at compile time. You could get around this by using the dynamic key word, but that's just working AROUND the problem.
public class SqlRepository
{
private dynamic dataContext;
public SqlRepository(DbContext dataContext) {
this.dataContext = dataContext;
}
...
}
What you need to do is change the signature to use your SqlDataContext:
public class SqlRepository
{
private SqlDataContextdata Context;
public SqlRepository(SqlDataContextdata Context) {
this.dataContext = dataContext;
}
...
}
because DbContext does not contain those methods, only your SqlContext does. and your sqlcontext is bound to DbContext at runtime.