Custom Cultures and .NET Framework Language Packs

The .NET Framework draws the resources it needs from both the operating system and the framework's resources. In particular resources, such as exception messages, PrintPreviewDialog, CultureInfo.DisplayName, and RegionInfo.DisplayName are all drawn from the .NET Framework Language Pack that matches the CultureInfo.CurrentUICulture. Of course, for supplemental custom cultures, no such language pack exists, so the resources fall back to English. You can do very little about this. Whereas it is technically possible to create your own .NET Framework Language Pack for your own language, there is no value in doing so because you cannot sign the assembly with the same key used to sign the .NET Framework assemblies. If your custom .NET Framework Language Pack does not use the same key, ResourceManager will not match your language pack satellite assemblies with the fallback assemblies in the .NET Framework. Consequently, any such custom .NET Framework Language Pack will be ignored.

This has a knock on effect if you use ClickOnce to deploy your Windows Forms applications because the majority of the ClickOnce interface is drawn from the .NET Framework Language Packs (see the "ClickOnce" section in Chapter 4, "Windows Forms Specifics"). Because you cannot create your own .NET Framework Language Packs, you cannot provide a ClickOnce user interface in your custom culture's language (with the exception of the ClickOnce bootstrapper dialogs).