c# - Converting TimeSpan to milliseconds in linq query -

i'm trying add timespan datetime in linq query using entity framework. i've got following code:

edit

timeslotsis icollection<timeslot>

timeslot has properties datetime start , timespan duration

var linq = s in schedulesbase            join c in channelbase on s.channelid equals c.channelid            select new            {                 ...                 timeslots = s.timeslots,                 ...            };  var timeslots = linq.selectmany(t => t.timeslots);  return s in timeslots        select new resources.event        {             ...             end = dbfunctions.addseconds((datetime?)s.start, (int32?)s.duration.seconds)             ...        }; 

it compiles fine doesn't add time s.duration.seconds end. since following code works

end = dbfunctions.addseconds((datetime?)s.start, 500) 

and behaves expected must doing wrong conversion timespan seconds.

what doing wrong in first case?

i suspect problem you're using seconds instead of totalseconds. seconds property gives value in range [-59, 59] - 5 minutes , 30 seconds return 30, not 330, example.

try:

end = dbfunctions.addseconds((datetime?)s.start, (int32?)s.duration.totalseconds)