错误。实体类型 List`1 不是当前上下文模型的一部分

Question

您好，我收到错误实体类型 List`1 不是以下代码行中当前上下文模型的一部分

 if (bureauEntities.Entry(subscription).State == EntityState.Detached)

 public ActionResult UnSubscribe(int subscriptionTypeId, int companyId)
    {
        if (ModelState.IsValid)
        {
              using (BUREAUEntities bureauEntities = new BUREAUEntities())
                {
                    var subscription = new SubcriptionRepository()
                   .AllIncluding(x => x.Exchanges, x => x.Users)
                   .ToList<Avanade.Bureau.DataAccessLayer.DatabaseModel.Subscription>().ToList<Avanade.Bureau.DataAccessLayer.DatabaseModel.Subscription>()
                   .Where(x => x.SubscriptionTypeId == subscriptionTypeId && x.CompanyId == companyId)// put where clasue here
                   .ToList<Avanade.Bureau.DataAccessLayer.DatabaseModel.Subscription>();


                    if (bureauEntities.Entry(subscription).State == EntityState.Detached)
                    {
                        // bureauEntities.Subscriptions.Attach(subscription);
                    }
                    //bureauEntities.Subscriptions.Remove(subscription);
                    bureauEntities.SaveChanges();

                }
}

谁能告诉我代码有什么问题？

Answer 1

DbContext.Entry(object) 需要一个对象。你传递给它一个List<>。如果您希望 LINQ 方法只返回一个值，请将 `.FirstOrDefault() 附加到查询中