数据关联-类不检索关联类的数据。

Question

我有两个班，专辑和艺术家。专辑可以有很多艺术家和艺术家可以在许多专辑。我为视图模型类和从数据库检索数据的方法都设置了导航属性，确保包含关联数据。下面是类和方法。当调用Index或Details操作时，都会显示艺术家属性的计数为零。应该是一位艺术家。不知道我错过了什么。

public class AlbumController : Controller
    {
         Manager m = new Manager();
        // GET: Album
        public ActionResult Index()
        {
            var allAlbums = m.AlbumGetAll();
            return View(allAlbums);
        }

        // GET: Album/Details/5
        public ActionResult Details(int id)
        {
            var album = m.AlbumGetById(id);
            return View(album);
        }
}

public class AlbumWithDetailViewModel:AlbumBaseViewModel
   {
      public AlbumWithDetailViewModel()
      {
         Artists = new List<ArtistBaseViewModel>();
         Tracks = new List<TrackBaseViewModel>();
      }

      public IEnumerable<ArtistBaseViewModel> Artists { get; set; }
      public IEnumerable<TrackBaseViewModel> Tracks { get; set; }
   }

public class ArtistWithDeatilViewModel:ArtistBaseViewModel
   {
      public ArtistWithDeatilViewModel()
      {
         Albums = new List<AlbumBaseViewModel>();
      }
      public IEnumerable<AlbumBaseViewModel> Albums { get; set; }
   }

///////////// Album Methods /////////////
      public IEnumerable<AlbumWithDetailViewModel> AlbumGetAll()
      {

         return mapper.Map<IEnumerable<AlbumWithDetailViewModel>>(ds.Albums.OrderBy(a => a.Name));
      }

      public AlbumWithDetailViewModel AlbumGetById(int id)
      {
         return mapper.Map<AlbumWithDetailViewModel>(ds.Albums.Include("Artists").SingleOrDefault(a => a.Id == id));
      }

Answer 1

事实证明，这个问题与我对设计模型类所做的更改有关。一旦我从表中删除了样本数据并重新加载它们，这些关联就开始工作了。