Question

我是EF新手，我有以下疑问：

List<Test.MemberAccount> userAccounts = new List<Test.MemberAccount>();
using (var context = new CoopEntities1())
{
    var query = from s in context.MemberAccount
                join sa in context.AccountType on s.account_type_id equals sa.id
                where s.member_guid == memberID
                select s;

    userAccounts = query.ToList();
}

return userAccounts;

问题是当我加载页面时出现以下错误：

＆＃34; ObjectContext实例已被处理，不能再用于需要连接的操作。＆＃34;

任何帮助都会很棒。

详细错误：

AccountType = '((new System.Collections.Generic.Mscorlib_CollectionDebugView<Test.MemberAccount>
(userAccounts)).Items[0]).AccountType' 
threw an exception of type 'System.ObjectDisposedException'

Answer 1

没有急切地加载AccountType。由于您坚持使用查询语法，因此它将如下所示：

List<Test.MemberAccount> userAccounts = new List<Test.MemberAccount>();
using (var context = new CoopEntities1())
{
    var query = (from s in context.MemberAccount
                join sa in context.AccountType on s.account_type_id equals sa.id
                where s.member_guid == memberID
                select s).Include("AccountType");

    userAccounts = query.ToList();
}

return userAccounts;

如果缺少intellisense，请确保包含以下using语句：

using System.Data.Entity;

Answer 2

您的会员帐户需要eagerly load AccountType：

List<Test.MemberAccount> userAccounts = new List<Test.MemberAccount>();
using (var context = new CoopEntities1())
{
    userAccounts = context.MemberAccount
                    .Where(m => m.member_guid == memberID) 
                    .Include(m => m.AccountType) 
                    .ToList();
}

return userAccounts;

ObjectContext实例已被处置错误

2 个答案: