Globalization and localization in ASP.NET Core – Part 1

Here, this post is about my experience in the globalization and localization in core application.

This is series of Post for localization / globalization

Part 1 – Introduction

Part 2 – ASP.NET Core ways of Localization / Globalization

Part 3 – Old trustworthy ResourseManager

First for the fresher folks, let me explain what’s globalization and localization

Say, you need an web application which caters to different language say English and French. Greeting like “Hello Friend” needs to be translated to “salut l’ami” in french. How do we do it, simple. Create file with Name Value, on for English and other for French.

TextTranslate-English.txt -> Greeting =  “Hello Friend”

TextTranslate-English.txt -> Greeting =  “salut l’ami”

In Code -> var message  = TextTranslate[“Greeting”]

Base on the language, it will pick from the respective file. This is the idea of Globalization and localization. Dotnet folks figure this out long before in .NET 1.1 framework and in same can be done with Resource files in .NET.

In Visual Studio, you can add resource file to your project.

This resource file contain the key and value. Say, here Key is “Hello” and Value is “Hello-en-us”

Similarly, you can add different culture resource file.

In dotnet, language has more than text, it’s how you write dates, format numbers, currency symbols, etc. So, they call collection of this as culture

e.g. US English = 12/25/2017, UK English = 25/12/2017

Culture are denote by two letter alphabets like en, or en-US, en-UK. That’s US English and UK English. es-ES is Spanish Spain and es-MX Spanish Mexico. If just es is mention, then it defaults to Spanish Spain, en defaults to en-US.

And the class which handle this is known as cultureinfo. The thread in runs your code has two properties CultureInfo and UICultureInfo

Culture is the .NET representation of the default user locale of the system. This controls default number and date formatting and the like.

UICulture refers to the default user interface language, a setting introduced in Windows 2000. This is primarily regarding the UI localization/translation part of your app.

You can get running thread Culture with following code

 CultureInfo cul = Thread.CurrentThread.CurrentCulture;
 CultureInfo culUI = Thread.CurrentThread.CurrentUICulture;

Now, In ASP.NET, say your server in running in UK and you got the request from France. How does ASP.NET application know, it have to serve french text?

Fortunately, in ASP.NET Core, there is middleware which does it for us. By default, it has three ways

  • QueryString
  • Cookie
  • AcceptLanguage Header




You can read Cookie as

The cookie format is c=%LANGCODE%|uic=%LANGCODE%, where c is Culture and uic is UICulture, for example: c=en-UK|uic=en-US


You can write cookie with following code

 new CookieOptions { Expires = DateTimeOffset.UtcNow.AddYears(1) });


When browser makes the request to website, it will send accept-language header. As seen in Chrome debug window -> Network -> Request Headers


You can read more about it here,

This middleware would set the thread.currentCulture and thread.currentUICulture using either QueryString, Cookie or Accept-Language Header

Once current culture is set, Date.ToString() will return date as per Current culture. In en-US it would be 12/25/2017 and en-UK, it would be 25/12/2017

Next post we will see, how to implement localization package and how to use it.

2 thoughts on “Globalization and localization in ASP.NET Core – Part 1

  1. Pingback: Globalization and localization in ASP.NET Core – Part 2 | Technical Insanity

  2. Pingback: Globalization and localization in ASP.NET Core – Part 3 | Technical Insanity

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