iOS13, Swift 5+， WWDC2019 https://developer.apple.com/videos/play/wwdc2019/403/

用户可以独立于操作系统语言选择应用程序的首选语言。

你可以使用这些:

    // Returns a list of the user's preferred languages.
    // Maybe more than (or none of) your app supports!
    Locale.preferredLanguages

    // a subset of this bundle's localizations, re-ordered into the preferred order
    // for this process's current execution environment; the main bundle's preferred localizations
    // indicate the language (of text) the user is most likely seeing in the UI
    Bundle.main.preferredLocalizations



    // The current running app language
    Bundle.main.preferredLocalizations.first

    // list of language names this bundle appears to be localized to
    Bundle.main.localizations

我试图为自己找出正确的解决办法。当我使用Locale.preferredLanguages.first从你的应用程序设置返回首选语言。

如果你想从用户设备设置中了解语言，你应该使用下面的字符串:

斯威夫特3

let currentDeviceLanguage = Locale.current.languageCode
// Will return the optional String

要展开并使用，请看下面这行:

if let currentDeviceLanguage = Locale.current.languageCode {
    print("currentLanguage", currentDeviceLanguage)

    // For example
    if currentDeviceLanguage == "he" {
        UIView.appearance().semanticContentAttribute = .forceRightToLeft
    } else {
        UIView.appearance().semanticContentAttribute = .forceLeftToRight
    }
}

这可能会给你你想要的:

NSLocale *locale = [NSLocale currentLocale];

NSString *language = [locale displayNameForKey:NSLocaleIdentifier 
                                         value:[locale localeIdentifier]];

它会在语言本身中显示语言的名称。 例如:

Français (France)
English (United States)

根据苹果文档

NSUserDefaults* defs = [NSUserDefaults standardUserDefaults];
NSArray* languages = [defs objectForKey:@"AppleLanguages"];
NSString* preferredLang = [languages objectAtIndex:0];

@amir在Swift中的回应:

// Get language prefered by user
let langageRegion = NSLocale.preferredLanguages().first!
let languageDic = NSLocale.componentsFromLocaleIdentifier(langageRegion)
let language = languageDic[NSLocaleLanguageCode]

斯威夫特3

let locale = Locale.current
let code = (locale as NSLocale).object(forKey: NSLocale.Key.countryCode) as! String?
print(code!)