We sometimes wish to make our web API return error messages or other types of string data in different languages. The process for this is similar to MAUI and WinForms, we just do the following

• Create a folder names Resources in our web APIT project
• Add a RESX file, which we’ll name AppResources.resx. This will be the default language, so in my case this will include en-GB strings
• Ensure the file has a Build Action of Embedded resource and Custom Tool of ResXFileCodeGenerator
• Add a name (which is the key to your resource string) and then add the value. This is the string (i.e. the translated string) for the given key
• Let’s add another RESX file, but this type name it AppResources.{language identifier}.resx, for example AppResources.de-DE.resx which will contain the German translation of the key/name’s
• Again ensure the Build Action and Custom Tool are correctly set

The ResXFileCodeGenerator will generate properties in the AppResources class for us to access the resource strings. For example

AppResources.ExceptionMessage

If we need to test our translations without changing our OS language, we simply use code such as the following in the Program.cs of the web API

AppResources.Culture = new CultureInfo("de-DE");