C# linq 问题:分组后汇总时间差 报错 求救
var resutl= from a in t_HaltRd
group a by new { a.Id } into f
select new
{
f.Key.Id,
HaltCount = f.Count(),
HaltTimeSum = f.Sum(p => (p.EndTime - p.StartTime).TotalMinutes),
};