问无法保存对上下文的更改

EN

  public class MovieController : Controller
  {
      Connect connection = new Connect();
      Movie movie = new Movie();

      [HttpPost]
      public ActionResult Create(Movie moviecreated)
      {
        try
        {
            // TODO: Add insert logic here
            connection.Connection().AddObject(moviecreated);
            connection.Connection().Context.SaveChanges();
            return RedirectToAction("Index");
        }
        catch
        {
            return View(movie);
        }
       }
    }

public class Connect
{
    public ObjectSet<Movie> Connection() 
    { 
        var connStr = ConfigurationManager.ConnectionStrings["Entities"]; 
        ObjectContext context = new ObjectContext(connStr.ConnectionString); 
        var movieContext = context.CreateObjectSet<Movie>(); 
        return movieContext; 
    } 
 }