Culture code

A culture code identifies the language and region whose conventions an application should use. In a world-ready application, it can affect visible strings, date and number formats, and sort order. Supporting a new culture should not require changing application logic: culture-specific resources supply the translated content. section 12.5.1 section 12.5.4

For localized sensor descriptions, the unqualified SensorNames.restext file supplies default resources, while SensorNames.es-MX.restext supplies Spanish-language resources for Mexico. A build places the es-MX resources in a culture-specific satellite assembly. ResourceManager selects resources using UI culture; ordinary culture controls formatting, including dates and times. Usually, set both to the same code. section 12.3 section 12.4

var cultures = new[] { "en-US", "es-MX" };                 #1
var localizationOptions = new RequestLocalizationOptions()
  .SetDefaultCulture(cultures[0])                          #2
  .AddSupportedCultures(cultures)
  .AddSupportedUICultures(cultures);                       #3
app.UseRequestLocalization(localizationOptions);

Configure ASP.NET Core with a default culture and explicit lists of supported cultures and UI cultures, then add request-localization middleware. Its built-in providers check the query string first, then a cookie, then the Accept-Language header. section 12.4

Keep the client and presentation behavior aligned:

• Set CurrentCulture and CurrentUICulture when producing local output. Also send an Accept-Language header when calling a service: setting the current thread’s culture does not make HttpClient send one automatically. section 12.5.1 section 12.6
• Do not assemble user-facing labels by concatenating fixed pieces. Resource strings can hold placeholders so a translation can choose where a value appears. section 12.5.1
• Check assumptions beyond translation. The ar-SA culture can produce a lunar-calendar date, and right-to-left output may not display correctly in every console. section 12.5.3

A culture code is not a complete policy for every regional choice. Temperature units, addresses, and paper sizes need separate consideration. Use the invariant culture for stored numbers and backend data that must not vary with a user’s culture. section 12.5.1 section 12.5.4