c# - 一个上下文引用 LINQ 查询抛出多个引用异常 - BUG？

Question

我正在使用以下代码:

using(MainEntities mainContext = new MainEntities())
{
    return (from member in mainContext.aspnet_Membership
            where adminGroupUserIDs.Contains(member.UserId)
            select new
            {
                FullName = member.FirstName + " " + member.LastName,
                UserName = (from user in mainContext.aspnet_Users
                            where user.UserId == member.UserId
                            select user.UserName)
            }).ToList(); 
}

哪里adminGroupUserIDs是一个 IQueryable<GUID>由对 MainEntities 的不同实例的查询形成.

对于此查询，LINQ 会提示:

The specified LINQ expression contains references to queries that are associated with different contexts.

有什么想法吗？

Answer 1

我无法从您在此处显示的代码中确定，但我很确定 adminGroupUserIDs 是另一个尚未检索的查询的结果，并且是使用MainEntities 的不同实例。您不能混合来自不同上下文的查询，甚至不能混合来自同一上下文类的不同实例。尝试将其更改为以下内容:

var loadedAdminGroupUserIDs = adminGroupUserID.ToArray();

using(MainEntities mainContext = new MainEntities())
{
    return (from member in mainContext.aspnet_Membership
            where loadedAdminGroupUserIDs.Contains(member.UserId)
            select new
            {
                FullName = member.FirstName + " " + member.LastName,
                UserName = (from user in mainContext.aspnet_Users
                            where user.UserId == member.UserId
                            select user.UserName)
            }).ToList(); 
}