本文介绍了Linq:int之和的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我得到"不能将空值分配给类型为System.Int32的成员,这是非空值类型",当我执行空语句的Sum()时.ResultView可以正常工作,但是可以
I am getting "The null value cannot be assigned to a member with type System.Int32 which is a non-nullable value type" When executing Sum() of my empty statement.ResultView works fine, but either
var r = from v in DataContext.Visits
join bs in DataContext.BaseContents on v.BaseContentID equals bs.Id
where (bs.CreatedBy == userId) && (v.DateVisited.Year == workDate.Year) &&
(v.DateVisited.Month == workDate.Month) && (v.DateVisited.Day == workDate.Day) &&
(v.IsPreviewed == false) && (bs.ProfileProjectId != null)
select v;
int? number = r.Sum( v => v.Counter);
两个
var r = from v in DataContext.Visits
join bs in DataContext.BaseContents on v.BaseContentID equals bs.Id
where (bs.CreatedBy == userId) && (v.DateVisited.Year == workDate.Year) &&
(v.DateVisited.Month == workDate.Month) && (v.DateVisited.Day == workDate.Day) &&
(v.IsPreviewed == false) && (bs.ProfileProjectId != null)
select v.Counter;
int? number = r.Sum(v);
失败,具有相同的例外.
fails with same exception.
推荐答案
尝试一下(已更新):
int number = r.Sum(v => (int?)v.Counter) ?? 0;
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