How do I use NodaTime to string format with a Culture's ShortDatePattern?

Question

With a C# DateTime and Culture I can format to a string with:

DateTime exampleDate = DateTime.Now;
CultureInfo culture = new CultureInfo("fr-FR");
String datetimeFormat = exampleDate.ToString(culture.DateTimeFormat.ShortDatePattern));

How do I achieve the same with NodaTime? I've tried combinations along the lines of (doesn't compile - ToString requires two parameters with NodaTimef):

DateTimeZone timeZone = DateTimeZoneProviders.Tzdb["fr-FR"];
ZonedDateTime nowZonedDateTime = new ZonedDateTime(Instant.FromDateTimeUtc(DateTime.Now.ToUniversalTime()), timeZone);
String nodaFormat = nowZonedDateTime.LocalDateTime.ToString(culture.DateTimeFormat.ShortDatePattern));

I've also tried combinations around the documentation which indicates I need to use "d" to format to short date (this throws an exception):

String nodaFormat = nowZonedDateTime.LocalDateTime.ToString("d", culture));

What am I missing?

Answer 1

Firstly, there isn't a timezone with the ID of fr-FR in TZDB, did you mean Europe/Paris?

Secondly, ToString actually accepts 2 parameters - a pattern string and an IFormatProvider, which can be your CultureInfo. So you're very nearly there - you just need to pass in the culture as the second argument:

CultureInfo culture = new CultureInfo("fr-FR");
DateTimeZone timeZone = DateTimeZoneProviders.Tzdb["Europe/Paris"];
ZonedDateTime nowZonedDateTime = new ZonedDateTime(Instant.FromDateTimeUtc(DateTime.Now.ToUniversalTime()), timeZone);
String nodaFormat = nowZonedDateTime.LocalDateTime.ToString(culture.DateTimeFormat.ShortDatePattern, culture);
// nodaFormat would be "27/12/2019"

Answer 2

The NodaTime documentation lists two APIs for the, a BCL-based one as described in the answer by @Sweeper and a pattern-based API, which it recommends as the preferred approach. First you create a pattern instance, then you use that pattern to format your LocalDate instance.

var frenchCulture = CultureInfo.CreateSpecificCulture("fr-FR");
var frenchDatePattern = LocalDatePattern.Create("d", frenchCulture);
String nodaFormat = frenchDatePattern.Format(nowZonedDateTime.LocalDateTime);

If you have multiple date to format in the same style you can reuse the same datePatternObject.