C# linq group by id和金额之和为空（未定义）

当我将这个结果绑定到我的剑道mvc网格，，，，时，有人知道为什么会发生这种情况吗

还尝试了以下一个但未定义的相同结果：

var approverlist = _db.ApprvRejClaimTravelCashByApproverIdIPhone(ProjectSession.CompanyUserId, ProjectSession.CompanyId, Status).AsEnumerable().ToList();`
var results =
    from item in approverlist
    group item by item.ClaimId
        into g
        select new
        {
            ClaimId = g.Key,
            Name = g.First().Name,
            Amount = g.Sum(s => s.Amount),
            Description = g.First().Description,
            Status = g.First().Status,
            CreatedDate = g.First().CreatedDate,
            SubmitedDate = g.First().SubmitedDate,
            FullName = g.First().FullName,
            ApproverStatus = g.First().ApproverStatus,
            CurrencySymbol = g.First().CurrencySymbol,
            chkbox = g.First().chkbox,
            IsHierarchy = g.First().IsHierarchy,
            ColumnCategory = g.First().ColumnCategory,
            ColumnCategoryCode = g.First().ColumnCategoryCode
        };

return Json(results.ToDataSourceResult(request));

---

金额是值类型还是可为空？如果你把s=>1，你会得到计数值吗？它来自我的SP resultset，如下所示：public Nullable Amount{get；set；}试着把s=>s.Amount？？0（当为null时为零）放进去，但是我在Amount列中为所有记录都有值，我还是必须把它放进去？也许你有空值，或者你使用的网格（我没有使用过）不适合使用null。我不确定它是否能为您解决问题，但我正在尝试调试。如果它修复了，我会给它一个答案

var results = from x in approverlist
              group x.ClaimId by new { x.ClaimId, x.Name, x.Description, x.Status, x.CreatedDate, x.SubmitedDate, x.FullName, x.ApproverStatus, x.CurrencySymbol, x.chkbox, x.IsHierarchy, x.ColumnCategory, x.ColumnCategoryCode }
              into g
              select new { g.Key.ClaimId, g.Key.Name, Amount = g.Sum(), g.Key.Description, g.Key.Status, g.Key.CreatedDate, g.Key.SubmitedDate, g.Key.FullName, g.Key.ApproverStatus, g.Key.CurrencySymbol, g.Key.chkbox, g.Key.IsHierarchy, g.Key.ColumnCategory, g.Key.ColumnCategoryCode };