Develop Reference

AWS lambda C# core CultureInfo ToString issue

I am trying to change the format of ToLongDateString to be in my local culture (da-DK).
For now I am doing the following, and if it can be done in a better way, then it will be very appreciated:
CultureInfo cCulture = new CultureInfo("da-DK");
string dateTimeStr = freeSeat.FreeDate.ToLongDateString().ToString(cCulture);
This works as expected on my local development environment, but when I deploy it to AWS lambda, I just get the English culture format. I am pretty sure the issue is that in AWS the C# core code is running on Linux.
I hope someone can give me some input how to solve this.

The ToLongDateString method returns a string formatted according to the current thread culture. Calling ToString method later is useless.
Do it like this:
CultureInfo cCulture = new CultureInfo("da-DK");
string format = cCulture.DateTimeFormat.LongDatePattern;
string dateTimeStr = freeSeat.FreeDate.ToString(format, cCulture);

DateTime.ToString format inconsistent between Web App and Windows Service

We are experiencing weird behaviour between a web application and windows service when trying to perform a ToString() on a DateTime value.
See the example below.
DateTime parsedReportDate;
reportDate = DateTime.Now.ToString("yyyyMMdd");
reportDateWithSlash = DateTime.Now.ToString("dd/MM/yyyy");
if (DateTime.TryParse(MyDateValue, out parsedReportDate))
{
reportDate = parsedReportDate.ToString("yyyyMMdd");
reportDateWithSlash = parsedReportDate.ToString("dd/MM/yyyy");
}
--reportDateWithSlash on Web Application: 28/03/2017
--reportDateWithSlash on Windows Service: 28-03-2017
The Windows Service calls the same function as the Web Application does, so why is the formatting different then?

The formatting of dates to strings uses a CultureInfo object to know what format to use.
Each Thread has a Thread.CurrentCulture property.
You can find out what CultureInfo the current Thread is set by getting the current Thread using Thread.CurrentThread and then inspecting it's Thread.CurrentCulture property.
public class Program
{
public static void Main()
{
Console.WriteLine(Thread.CurrentThread.CurrentCulture.Name);
}
}
https://dotnetfiddle.net/dsA3VT
Output: en-US
You can set the CultureInfo for the the Thread, or pass it with each call to ToString.
Setting Thread.CultureInfo
You can set the Thread.CultureInfo using the same property as you use to read it.
Thread.CurrentCulture = new CultureInfo("en-gb");
Unfortunately .Net Fiddle doesn't support changing thread properties.
I didn't know this, but bradbury9 pointed out that since .net 4.6 you can set the CultureInfo.CurrentCulture property as well.
CultureInfo.CurrentCulture = CultureInfo.CreateSpecificCulture("nl-NL");
Unfortunately .Net Fiddle doesn't support changing the culture this way either.
Passing CultureInfo to ToString
'DateTime.ToString' has overloads which can take an IFormatProvider, and CultureInfo impliments IFormatProvider.
DateTime.Now.ToString(new CultureInfo("en-gb"));
https://dotnetfiddle.net/qkS5HF
public class Program
{
public static void Main()
{
var dateTime = DateTime.Now;
Console.WriteLine(Thread.CurrentThread.CurrentCulture.Name);
Console.WriteLine(dateTime.ToString(CultureInfo.InvariantCulture));
Console.WriteLine(dateTime.ToString(new CultureInfo("en-us")));
}
}
Output:
en-US
03/28/2017 09:43:49
3/28/2017 9:43:49 AM

The problem must come from having different cultures. Using the DateTime.ToString (String, IFormatProvider) overload with the CultureInfo.InvariantCulture property should solve the problem:
DateTime.Now.ToString("dd/MM/yyyy", System.Globalization.CultureInfo.InvariantCulture);

it may be what is calling the Windows service is formatting the date. the code certainly is clear enough. Try debugging the windows service by attaching to the running process and see what it generates. If your service consumer is a web app, look at F12 developer tools and see what is getting sent back int he response stream.

Migrating from DDay.Ical.Net to Ical.Net

Hi I am migrating from DDay.ical to Ical.Net nuget pacakages but I get stuck in the following code which add Timezone in DDay.Ical calendar please help
Previous code:
List<DOAppointment> lst = objResponse.Appointments;
string timeZoneName = objResponse.UserTimezone;
iCalendar calendar = new DDay.iCal.iCalendar();
var timeZone = TimeZoneInfo.FindSystemTimeZoneById(timeZoneName);
calendar.AddTimeZone(iCalTimeZone.FromSystemTimeZone(timeZone));
Migrating into Ical.Net:
List<DOAppointment> lst = objResponse.Appointments;
string timeZoneName = objResponse.UserTimezone;
Ical.Net.Calendar calendar = new Ical.Net.Calendar();
var timeZone = TimeZoneInfo.FindSystemTimeZoneById(timeZoneName);
ITimeZone tzID = timeZone;
calendar.AddTimeZone(tzID);
Here I know that calendar.AddTimezone will take ITimezone but how to pass it I am not getting please help.

VTimeZone is the concrete implementation of the ITimeZone interface. The ical.net example would look like this:
var calendar = new Ical.Net.Calendar();
// ical.net supports BCL time zones as well as IANA time zones
calendar.AddTimeZone(new VTimeZone(objResponse.UserTimezone));
In the future, I may change the VTimeZone constructor to throw an exception if the time zone string doesn't match anything known. Right now, though, it's pretty dumb. Behind the scenes, ical.net will default to the system time zone that the code is running on, if all else fails. That's probably not good.
I also added a wiki page with an adaptation of your question:
https://github.com/rianjs/ical.net/wiki/Working-with-time-zones

Datetime error in iis 7 server

I have screen in c# asp.net webapplication, where i add news on particular dates.And can edit those dates also.It workes in my local sytem.But shows datetime error when it was running in iis 7 server(Used sql database).And i knew that the short date and long date format in server was different from local system.So i changed date format in local system same as in iis.But still it is working properly.

Instead of guessing culture settings write code that sets one you need before reading from database/restore after unsing Thread.CurrentCulture property. Simialr to code below (need to also use CurrentUICulture, chose cuture you need and wrap code around setting/restoring into try/finally for real code)
var oldCulture = Thread.CurrentThread.CurrentCulture;
Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
// read from DB
...
Thread.CurrentThread.CurrentCulture = oldCulture;

Why does sometimes DateTime.TryParse work and other time only DateTime.ParseExact work?

I have two laptops both with windows xp sp3, vs 2010 and target framework .Net 3.5. When processing DateTime variable, I found that with laptop1
DateTime oldOrderDate;
string strnewdate = string.Empty;
CultureInfo provider = CultureInfo.InvariantCulture;
if (DateTime.TryParse(items[1], out oldOrderDate))
strnewdate = oldOrderDate.ToString("yyyy-MM-dd");
returned an exception "string was not recognized as a valid datetime" , but the codes below:
oldOrderDate = DateTime.ParseExact(items[1], "dd/MM/yyyy", provider);
strnewdate = oldOrderDate.ToString("yyyy-MM-dd");
works. OTOH, with laptop2,
oldOrderDate = DateTime.ParseExact(items[1], "dd/MM/yyyy", provider);
strnewdate = oldOrderDate.ToString("yyyy-MM-dd");
returned an exception "string was not recognized as a valid datetime" , but the code below:
if (DateTime.TryParse(items[1], out oldOrderDate))
strnewdate = oldOrderDate.ToString("yyyy-MM-dd");
works. So, my question is how I should do processing of a DateTime variable to work in both laptops. I'd really appreciate any advice you could give me. Thank's in advance.

I am not sure but look at the regional settings of date and time in control panel. In my systems they also differ and hence different results.