显然，解决方案依赖于，例如

[[NSLocale preferredLanguages] objectAtIndex:0]

通常工作正常，并返回当前设备语言。

但在某些情况下，它可能会产生误导:

如果你想要获取这个值的应用程序已经改变了语言，例如使用这样的代码:

NSString *lg = @"en"; // or anything like @"en", @"fr", etc.
[[NSUserDefaults standardUserDefaults] 
    setObject:[NSArray arrayWithObjects:lg, nil]  
    forKey:@"AppleLanguages"]

在这种情况下，[NSLocale preferredLanguages]实际上返回这个特定应用程序的首选语言集(和使用)，而不是当前设备语言!

和…在这种情况下，正确获得实际当前设备语言(而不是之前在应用程序中设置的语言)的唯一方法是首先清除NSUserDefaults中的@"appleLanguages"键，像这样:

[[NSUserDefaults standardUserDefaults]removeObjectForKey:@"AppleLanguages"];

然后，[NSLocale preferredLanguages]现在返回正确的值。

希望这对你有所帮助。

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
}

Swift 4的更新答案

let language = Bundle.main.preferredLocalizations.first

根据苹果文档

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

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)

iOS13, Swift 5+

Locale.preferredLanguages.first

iOS 9的解决方案:

NSString *language = [[NSLocale preferredLanguages] objectAtIndex:0];

language = "en-US"

NSDictionary *languageDic = [NSLocale componentsFromLocaleIdentifier:language];

languageDic将拥有所需的组件

NSString *countryCode = [languageDic objectForKey:@"kCFLocaleCountryCodeKey"];

countryCode = "US"

NSString *languageCode = [languageDic objectForKey:@"kCFLocaleLanguageCodeKey"];

密码: