无法将字符串识别为有效的DateTime服务器错误

Question

Below is my code

var result =
    (from SV in Tbl
     where (DateTimeOffset.Parse(SV.FieldName) >= DateTimeOffset.Parse(StartDate) 
     && DateTimeOffset.Parse(SV.FieldName) <= DateTimeOffset.Parse(EndDate))
     group SV by 1 into SVgrp
     select new { Count = SVgrp.Sum(p => p.Count) }).ToList()

The value of SV.FieldName = '19-06-2015' , StartDate = '2015-09-20T00:00:00Z' , EndDate = '2015-10-21T23:59:59Z'

On my development machine, this code works perfectly whereas on my server, its giving me error String was not recognized as a valid DateTime

Both my machines have date format set as English(India), Location as India and Timezone set as UTC.

I tried adding CultureInfo.InvariantCulture on all four Parse methods, but the error did not go.

Why am I getting this error on server only? How can it be solved?

Answer 1

I'm certain that the error comes when converting the value of s.FieldName = '19-06-2015'. The compiler assume that the format is MM-dd-yyyy and therefor 19 is seen as an invalid month number.

my suggestion will be to construct the date value, see below

    var result = (from SV in Tbl
           where (new DateTime(Convert.ToInt32(SV.FieldName.Substring(6, 4)), Convert.ToInt32(SV.FieldName.Substring(3, 2)), Convert.ToInt32(SV.FieldName.Substring(0, 2))) >= DateTimeOffset.Parse(StartDate) 
           && new DateTime(Convert.ToInt32(SV.FieldName.Substring(6, 4)), Convert.ToInt32(SV.FieldName.Substring(3, 2)), Convert.ToInt32(SV.FieldName.Substring(0, 2))) <= DateTimeOffset.Parse(EndDate))
           group SV by 1 into SVgrp
           select new { Count = SVgrp.Sum(p => p.Count) }).ToList()

this is not the best but it will do the job.

Answer 2

Try using DateTime.ParseExact(dateString, @"d/M/yyyy", System.Globalization.CultureInfo.InvariantCulture);

or

DateTime.TryParse(dateString,out date4);

if the parsing fails, it will not throw error, rather it returns false indicating that the parsing failed.