您是否已经有一个名为UsersInRoles的类?为什么不将属性添加到该类而不是使用局部类呢? Me.User与角色表中的用户有何关系? Me.User是与实例中的UserId关联的User吗?我认为我们还需要查看其他类，并且我们还需要知道什么代码会产生此错误.

Did you already have a class called UsersInRoles ? Why not add the property to that class instead of using a partial class ? How does Me.User relate to the users in roles table ? Me.User is the User associated with the UserId in the instance ? I think there''s other classes we need to see, and we also need to know what code generates this error.