可以在Locale结构上使用regionCode属性。

Locale.current.regionCode

它没有被记录为旧的NSLocaleCountryCode构造的替代品，但看起来它是。下面的代码检查所有已知区域设置的countryCode，并将它们与regionCode进行比较。它们是相同的。

public func ==(lhs: [String?], rhs: [String?]) -> Bool {
    guard lhs.count == rhs.count else { return false }

    for (left, right) in zip(lhs, rhs) {
        if left != right {
            return false
        }
    }

    return true
}

let newIdentifiers = Locale.availableIdentifiers
let newLocales = newIdentifiers.map { Locale(identifier: $0) }
let newCountryCodes = newLocales.map { $0.regionCode }

let oldIdentifiers = NSLocale.availableLocaleIdentifiers
newIdentifiers == oldIdentifiers // true

let oldLocales = oldIdentifiers.map { NSLocale(localeIdentifier: $0) }
let oldLocalesConverted = oldLocales.map { $0 as Locale }
newLocales == oldLocalesConverted // true

let oldComponents = oldIdentifiers.map { NSLocale.components(fromLocaleIdentifier: $0) }
let oldCountryCodes = oldComponents.map { $0[NSLocale.Key.countryCode.rawValue] }
newCountryCodes == oldCountryCodes // true

• 请参阅Wojciech N.'s answer以获得更简单的解决方案！*

与NSLocale Swift 3类似，您必须将覆盖类型Locale转换回其Foundation对应类型NSLocale，以便检索国家代码：

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

如果你确保你使用的是NSLocale而不是Locale示例，你可以使用countryCode属性：

let locale: NSLocale = NSLocale.current as NSLocale
let country: String? = locale.countryCode
print(country ?? "no country")
// > Prints "IE" or some other country code

如果你尝试在Swift Locale中使用countryCode，Xcode会给予你一个错误，建议你使用regionCode：

let swiftLocale: Locale = Locale.current
let swiftCountry: String? = swiftLocale.countryCode
// > Error "countryCode' is unavailable: use regionCode instead"

NSLocale.countryCode与Locale.regionCode相同
这是苹果的Locale实现。Locale.swift

/// Returns the region code of the locale, or nil if it has none.
    ///
    /// For example, for the locale "zh-Hant-HK", returns "HK".
    public var regionCode: String? {
        // n.b. this is called countryCode in ObjC
        if let result = _wrapped.object(forKey: .countryCode) as? String {
            if result.isEmpty {
                return nil
            } else {
                return result
            }
        } else {
            return nil
        }
    }

//MARK:- Get both country code and Mobile Phone number code
        var sendPhoneNumber = ""

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

                    if countryCode != ""
                    {
                       let getCode = self.getCountryPhonceCode(countryCode)

                        if getCode != ""
                        {
                            sendPhoneNumber = getCode + tfMobileNumber.text!
                            getOTP(getPhoneNumber: sendPhoneNumber)
                        }
                    }
                }

     //MARK:- Custom methods

     func getCountryPhonceCode (_ country : String) -> String
    {
        var countryDictionary  = ["AF":"93",
                                  "AL":"355",
                                  "DZ":"213",
                                  "AS":"1",
                                  "AD":"376",
                                  "AO":"244",
                                  "AI":"1",
                                  "AG":"1",
                                  "AR":"54",
                                  "AM":"374",
                                  "AW":"297",
                                  "AU":"61",
                                  "AT":"43",
                                  "AZ":"994",
                                  "BS":"1",
                                  "BH":"973",
                                  "BD":"880",
                                  "BB":"1",
                                  "BY":"375",
                                  "BE":"32",
                                  "BZ":"501",
                                  "BJ":"229",
                                  "BM":"1",
                                  "BT":"975",
                                  "BA":"387",
                                  "BW":"267",
                                  "BR":"55",
                                  "IO":"246",
                                  "BG":"359",
                                  "BF":"226",
                                  "BI":"257",
                                  "KH":"855",
                                  "CM":"237",
                                  "CA":"1",
                                  "CV":"238",
                                  "KY":"345",
                                  "CF":"236",
                                  "TD":"235",
                                  "CL":"56",
                                  "CN":"86",
                                  "CX":"61",
                                  "CO":"57",
                                  "KM":"269",
                                  "CG":"242",
                                  "CK":"682",
                                  "CR":"506",
                                  "HR":"385",
                                  "CU":"53",
                                  "CY":"537",
                                  "CZ":"420",
                                  "DK":"45",
                                  "DJ":"253",
                                  "DM":"1",
                                  "DO":"1",
                                  "EC":"593",
                                  "EG":"20",
                                  "SV":"503",
                                  "GQ":"240",
                                  "ER":"291",
                                  "EE":"372",
                                  "ET":"251",
                                  "FO":"298",
                                  "FJ":"679",
                                  "FI":"358",
                                  "FR":"33",
                                  "GF":"594",
                                  "PF":"689",
                                  "GA":"241",
                                  "GM":"220",
                                  "GE":"995",
                                  "DE":"49",
                                  "GH":"233",
                                  "GI":"350",
                                  "GR":"30",
                                  "GL":"299",
                                  "GD":"1",
                                  "GP":"590",
                                  "GU":"1",
                                  "GT":"502",
                                  "GN":"224",
                                  "GW":"245",
                                  "GY":"595",
                                  "HT":"509",
                                  "HN":"504",
                                  "HU":"36",
                                  "IS":"354",
                                  "IN":"91",
                                  "ID":"62",
                                  "IQ":"964",
                                  "IE":"353",
                                  "IL":"972",
                                  "IT":"39",
                                  "JM":"1",
                                  "JP":"81",
                                  "JO":"962",
                                  "KZ":"77",
                                  "KE":"254",
                                  "KI":"686",
                                  "KW":"965",
                                  "KG":"996",
                                  "LV":"371",
                                  "LB":"961",
                                  "LS":"266",
                                  "LR":"231",
                                  "LI":"423",
                                  "LT":"370",
                                  "LU":"352",
                                  "MG":"261",
                                  "MW":"265",
                                  "MY":"60",
                                  "MV":"960",
                                  "ML":"223",
                                  "MT":"356",
                                  "MH":"692",
                                  "MQ":"596",
                                  "MR":"222",
                                  "MU":"230",
                                  "YT":"262",
                                  "MX":"52",
                                  "MC":"377",
                                  "MN":"976",
                                  "ME":"382",
                                  "MS":"1",
                                  "MA":"212",
                                  "MM":"95",
                                  "NA":"264",
                                  "NR":"674",
                                  "NP":"977",
                                  "NL":"31",
                                  "AN":"599",
                                  "NC":"687",
                                  "NZ":"64",
                                  "NI":"505",
                                  "NE":"227",
                                  "NG":"234",
                                  "NU":"683",
                                  "NF":"672",
                                  "MP":"1",
                                  "NO":"47",
                                  "OM":"968",
                                  "PK":"92",
                                  "PW":"680",
                                  "PA":"507",
                                  "PG":"675",
                                  "PY":"595",
                                  "PE":"51",
                                  "PH":"63",
                                  "PL":"48",
                                  "PT":"351",
                                  "PR":"1",
                                  "QA":"974",
                                  "RO":"40",
                                  "RW":"250",
                                  "WS":"685",
                                  "SM":"378",
                                  "SA":"966",
                                  "SN":"221",
                                  "RS":"381",
                                  "SC":"248",
                                  "SL":"232",
                                  "SG":"65",
                                  "SK":"421",
                                  "SI":"386",
                                  "SB":"677",
                                  "ZA":"27",
                                  "GS":"500",
                                  "ES":"34",
                                  "LK":"94",
                                  "SD":"249",
                                  "SR":"597",
                                  "SZ":"268",
                                  "SE":"46",
                                  "CH":"41",
                                  "TJ":"992",
                                  "TH":"66",
                                  "TG":"228",
                                  "TK":"690",
                                  "TO":"676",
                                  "TT":"1",
                                  "TN":"216",
                                  "TR":"90",
                                  "TM":"993",
                                  "TC":"1",
                                  "TV":"688",
                                  "UG":"256",
                                  "UA":"380",
                                  "AE":"971",
                                  "GB":"44",
                                  "US":"1",
                                  "UY":"598",
                                  "UZ":"998",
                                  "VU":"678",
                                  "WF":"681",
                                  "YE":"967",
                                  "ZM":"260",
                                  "ZW":"263",
                                  "BO":"591",
                                  "BN":"673",
                                  "CC":"61",
                                  "CD":"243",
                                  "CI":"225",
                                  "FK":"500",
                                  "GG":"44",
                                  "VA":"379",
                                  "HK":"852",
                                  "IR":"98",
                                  "IM":"44",
                                  "JE":"44",
                                  "KP":"850",
                                  "KR":"82",
                                  "LA":"856",
                                  "LY":"218",
                                  "MO":"853",
                                  "MK":"389",
                                  "FM":"691",
                                  "MD":"373",
                                  "MZ":"258",
                                  "PS":"970",
                                  "PN":"872",
                                  "RE":"262",
                                  "RU":"7",
                                  "BL":"590",
                                  "SH":"290",
                                  "KN":"1",
                                  "LC":"1",
                                  "MF":"590",
                                  "PM":"508",
                                  "VC":"1",
                                  "ST":"239",
                                  "SO":"252",
                                  "SJ":"47",
                                  "SY":"963",
                                  "TW":"886",
                                  "TZ":"255",
                                  "TL":"670",
                                  "VE":"58",
                                  "VN":"84",
                                  "VG":"284",
                                  "VI":"340"]
        if countryDictionary[country] != nil {
            return countryDictionary[country]!
        }

        else {
            return ""
        }

    }

iOS 16 *

print(Locale.current.region?.identifier)

iOS 16以下

print(Locale.current.regionCode)

示例：

var localCode: String? = ""
        
if #available(iOS 16, *)  {
    localCode = Locale.current.region?.identifier
} else {
    localCode = Locale.current.regionCode
}
print(localCode)

print(NSLocale.current.regionCode)