持久绑定实体框架c＃

Question

这是我当前拥有的c＃代码，由于某种原因，来自联接表Roles的RoleDescription不在Winforms下显示在网格中。我可以轻松地将filter var用作网格的数据源，但是随后我失去了更新网格内数据的功能。有任何建议，而我也在尝试寻找解决方案

var obj = from a in dbContext.Permissions
          join r in dbContext.Roles on a.RoleID equals r.RoleID
          select new
          {
              PermissionID = a.PermissionID,
              RoleID = a.RoleID,
              RoleDescription = r.RoleDescription,
              AddRecords = a.AddRecords,
              Edit = a.Edit,
              UpdateRecord = a.UpdateRecord,
              DeleteRecord = a.DeleteRecord,
              StopUpdateAfterDays = a.StopUpdateAfterDays,
              DisplayTasks = a.DisplayTasks,
              ProFormaInvoices = a.ProFormaInvoices
          };

var filter = obj;
filter = filter.Where(x => x.RoleID == id);

bs.DataSource = dbContext.Permissions.Local.ToBindingList();

radGridView1.DataSource = bs;