Result IExternalApplication.OnStartup(UIControlledApplication application) {
...
// I use the `/language RUS` key for revit.exe
// But I see that my add-in user the 'default' localization
// instead of 'ru'. Hm...
// Ok,I will check the CurrentCulture and CurrentUICulture
// values...
//
// Oops... Localization was changed by the `/language RUS`
// key, but not for that thread which shall to have this
// change! Why???
CultureInfo n = Thread.CurrentThread.CurrentCulture; // ru-RU
CultureInfo m = Thread.CurrentThread.CurrentUICulture; // en
// I can fix this problem myself:
// The CurrentUICulture switching fixes the problem, but
// why such problem occurs in Revit?
CultureInfo k = new CultureInfo("ru");
Thread.CurrentThread.CurrentUICulture = k;
// Now my add-in uses right localization.
...
}