C# 错误:ObjectContext实例已被释放,无法再用于需要连接的操作
我在C#中使用asp.net和EF4 我有一个与C# 错误:ObjectContext实例已被释放,无法再用于需要连接的操作,c#,entity-framework,entity-framework-4,linq-to-entities,objectdatasource,C#,Entity Framework,Entity Framework 4,Linq To Entities,Objectdatasource,我在C#中使用asp.net和EF4 我有一个与ObjectDataSource关联的详细视图 <asp:ObjectDataSource ID="uxEntityDataSourceAuthors" runat="server" SelectMethod="GetAuthors" TypeName="WebProject.Web.Cms.AdminCms.Sections.CmsContents.ContentInformation">
ObjectDataSource
关联的详细视图
<asp:ObjectDataSource ID="uxEntityDataSourceAuthors" runat="server"
SelectMethod="GetAuthors"
TypeName="WebProject.Web.Cms.AdminCms.Sections.CmsContents.ContentInformation">
</asp:ObjectDataSource>
知道我做错了什么以及如何修复吗?在获取数据之前,您正在关闭名为
上下文的CmsConnectionStringEntityDataModel
。请记住,AsEnumerable()
将返回一个惰性枚举数,当您返回并处理上下文时,没有从源中读取任何数据
使用ToArray()
(或ToList()
)确保在关闭源代码之前将数据放入内存。调用numerable不会枚举集合,它只是将其从IQeuryable
更改为IEnumerble
。您正在从数据库中提取数据之前处理ObjectContext。使用将枚举集合并获取数据的ToList()
。列表和数组方法分别称为ToList()和ToArray(),Id没有AsArray()(或AsList())只有ToList()。
public IEnumerable<CmsAuthor> GetAuthors()
{
if (Roles.IsUserInRole("CMS-AUTHOR"))
{
using (CmsConnectionStringEntityDataModel context = new CmsConnectionStringEntityDataModel())
{
// Display all Authors for specific logged-in User.
// Get Guid for current logged-in User.
MembershipUser myLoggedinUser = Membership.GetUser();
Guid myUserGuid = (Guid)myLoggedinUser.ProviderUserKey;
// Get list of Authors filtering my current logged-in User.
var myAuthorsForAuthor = from a in context.CmsAuthors
where a.UserId == myUserGuid
orderby a.LastName ascending
select a;
return myAuthorsForAuthor.AsEnumerable();
}
}
return null;
}
The ObjectContext instance has been disposed and can no longer be used for operations that require a connection.