public override int SaveChanges()
        {
            var now = DateTime.Now;

            this.ChangeTracker.DetectChanges();
            foreach (var item in this.ChangeTracker.Entries()
                                  .Where(i => i.State == EntityState.Added || i.State == EntityState.Modified)
                                  .Where(i => i as IEntityAutoDate != null))
            {
                if (item.State == EntityState.Added)
                {
                    (item as IEntityAutoDate).DateCreated = now;
                }
                (item as IEntityAutoDate).DateUpdated = now;
            }




            return base.SaveChanges();
        }