entity-framework - 匿名类型不能有多个同名属性

Question

我想通过 Entity Framework 绑定(bind)gridview，但它抛出错误就像-

An anonymous type cannot have multiple properties with the same name Entity Framwrok

这是我的方法。

public void UserList(GridView grdUserList)
{
    using (TreDbEntities context = new TreDbEntities())
    {

        var query =( from m in context.aspnet_Membership
                    from u in context.aspnet_Users
                    join usr in context.Users
                    on new { m.UserId, u.UserId } 
                    equals new { usr.MembershipUserID, usr.UserId }
                    into UserDetails
                    from usr in UserDetails
                    select new { 
                       CreationDate = m.CreateDate,
                       email = m.Email,
                       UserName = u.LoweredUserName,
                       Name = usr.FirstName + usr.LastNameLastName,
                       Active=usr.IsActive
                    }).ToList();
    }
}

这里显示错误。 usr.UserId。

Answer 1

直接问题在于匿名类型new { m.UserId, u.UserId }:同名两次。您可以通过提供显式属性名称来解决此问题，例如:new { u1 = m.UserId, u2 = u.UserId }。

但是下一个问题是定义连接的两个匿名类型不会具有相同的属性名称，因此最终的修复是这样的:

public void UserList(GridView grdUserList)
{
    using (TreDbEntities context = new TreDbEntities())
    {
        var query =( from m in context.aspnet_Membership
                    from u in context.aspnet_Users
                    join usr in context.Users
                    on new { u1 = m.UserId, u2 = u.UserId } 
                    equals new { u1 = usr.MembershipUserID, u2 = usr.UserId }
                    into UserDetails
                    from usr in UserDetails
                    select new { CreationDate = m.CreateDate,
                                 email = m.Email,
                                 UserName = u.LoweredUserName,
                                 Name = usr.FirstName + " " + usr.LastName,
                                 Active = usr.IsActive
                               }
                   ).ToList();
    }
}