请参阅 Wojciech N.回答
以获得更简单的解决方案！

与 NSLocale Swift 3 ，您必须投射叠加类型区域设置回到
基金会对应 NSLocale 以便检索国家代码：

Similarly as in NSLocale Swift 3, you have to cast the overlay type Locale back to its Foundation counterpart NSLocale in order to retrieve the country code:

if let countryCode = (Locale.current as NSLocale).object(forKey: .countryCode) as? String {
    print(countryCode)
}