SWIFT-4

 // To get device default selected language. It will print like short name of zone. For english, en or spain, es.

let language = Bundle.main.preferredLocalizations.first! as NSString
print("device language",language)

对于获得用户设备当前语言使用以下它的代码，它为我工作。

NSString * myString = [[NSLocale preferredlanguage]objectAtIndex:0];

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
}

如果你正在寻找首选语言代码(“en”，“de”，“es”…)，和本地化的首选语言名称(当前地区)，这里有一个简单的Swift扩展:

extension Locale {
    static var preferredLanguageIdentifier: String {
        let id = Locale.preferredLanguages.first!
        let comps = Locale.components(fromIdentifier: id)
        return comps.values.first!
    }

    static var preferredLanguageLocalizedString: String {
        let id = Locale.preferredLanguages.first!
        return Locale.current.localizedString(forLanguageCode: id)!
    }
}

迅速:

let languageCode = NSLocale.currentLocale().objectForKey(NSLocaleLanguageCode) as? String

斯威夫特3

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