从iOS 9开始，如果你只想要语言代码而不需要国家代码，你将需要这种帮助函数——因为语言将包含国家代码。

// gets the language code without country code in uppercase format, i.e. EN or DE
NSString* GetLanguageCode()
{
    static dispatch_once_t onceToken;
    static NSString* lang;
    dispatch_once(&onceToken, ^
    {
        lang = [[[NSLocale preferredLanguages] objectAtIndex:0] uppercaseString];
        NSRegularExpression* regex = [NSRegularExpression regularExpressionWithPattern:@"^[A-Za-z]+" options:0 error:nil];
        NSTextCheckingResult* match = [regex firstMatchInString:lang options:0 range:NSMakeRange(0, lang.length)];
        if (match.range.location != NSNotFound)
        {
            lang = [lang substringToIndex:match.range.length];
        }
    });
    return lang;
}

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

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)

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
    }
}

简单Swift 3功能:

@discardableResult
func getLanguageISO() -> String {
    let locale = Locale.current
    guard let languageCode = locale.languageCode,
          let regionCode = locale.regionCode else {
        return "de_DE"
    }
    return languageCode + "_" + regionCode
}

-(NSString *)returnPreferredLanguage { //as written text

NSUserDefaults * defaults = [NSUserDefaults standardUserDefaults];
NSArray *preferredLanguages = [defaults objectForKey:@"AppleLanguages"];
NSString *preferredLanguageCode = [preferredLanguages objectAtIndex:0]; //preferred device language code
NSLocale *enLocale = [[NSLocale alloc] initWithLocaleIdentifier:@"en"]; //language name will be in English (or whatever)
NSString *languageName = [enLocale displayNameForKey:NSLocaleIdentifier value:preferredLanguageCode]; //name of language, eg. "French"
return languageName;

}