我正在从事的项目有很多与之相关的“查找”数据。因此,在处理此问题的类的第一次实例化时,我将所有查找数据都设置为静态IEnumerable,因此:
private static IEnumerable<Kiosk> _kiosks;
private static IEnumerable<Paper> _papers;
private static IEnumerable<NewsAgent> _newsAgents;
if (_kiosks == null)
_kiosks = db.Kiosks.Where(k => k.Active).OrderBy(k => k.Order).ToList();
if (_papers == null)
_papers = db.Papers.Where(p => p.Active).OrderBy(p => p.Name).ToList();
if (_newsAgents == null)
_newsAgents = db.NewsAgents.Where(n => n.Active).OrderBy(n => n.Order).ToList();
每次实例化这个类时,我都使用全新的DataContext为需要保存的数据类创建新的Linq实体。当我尝试提交这些更改时,出现以下错误:
"System.NotSupportedException: An attempt has been made to Attach or Add an entity that is not new, perhaps having been loaded from another DataContext. This is not supported."
我推测,在单独的DataContext上创建的缓存查找数据导致了这个问题。我认为这应该无关紧要,因为缓存的数据是用ToList持久化的,尽管每个实体都会在内部保存生成它的DataContext。
那么,如何将缓存的数据持久化以用于新的DataContext?
