[英]Cannot implicitly convert type 'System.Linq.IQueryable<AnonymousType#1>' to 'System.Linq.IQueryable<>'
[英]Cannot implicitly convert type 'System.Linq.IQueryable?
這是我的代碼,上面有錯誤
public ActionResult Edit(int id = 0)
{
KBS_Virtual_TrainingEntities db = new KBS_Virtual_TrainingEntities();
UsersContext ctx = new UsersContext();
UserProfile model = ctx.UserProfiles.Find(id);
List<CourseSubscription> user_Course_subscriptions = new List<CourseSubscription>();
foreach (UserSubscription sub in db.UserSubscriptions)
{
if (sub.ID == id)
{
user_Course_subscriptions.Add(sub.CourseSubscription);
}
}
List<CourseSubscription> not_subscribe = db.CourseSubscriptions.Except(user_Course_subscriptions);
var coursesList = from courses in not_subscribe
select new SelectListItem
{
Text = courses.Course.Name,
Value = courses.Course.ID
.ToString()
};
var CoursesTYPE = from CourseTypes in db.CourseTypes.ToList()
select new SelectListItem
{
Text = CourseTypes.Name,
Value = CourseTypes.ID
.ToString()
};
ViewBag.CourseID = coursesList;
ViewBag.type = CoursesTYPE;
return View(model);
}
我正在嘗試使用上述代碼查找當前用戶未訂閱的課程訂閱,但無法正常工作?
您在Except
函數的結果中缺少ToList
。 像這樣執行ToList
:
List<CourseSubscription> not_subscribe = db.CourseSubscriptions.Except(user_Course_subscriptions).ToList();
或者因為在您的代碼中您不需要執行任何需要列表的操作,所以只需對其進行var
更改或為其分配正確的類型,例如IQueryable<CourseSubscription>
。
var not_subscribe = db.CourseSubscriptions.Except(user_Course_subscriptions);
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