Swift - 获取国家/地区列表 - >致命错误：无法解包Optional.None

Question

几天前我问过如何获取Swift中的国家列表，你解决了它的第一部分（这里：Swift - Get list of countries），但是我无法获得最终的国家/地区列表，因为它给出了一个错误：

var countries: NSMutableArray = NSMutableArray()
countries = NSMutableArray(capacity: (NSLocale.ISOCountryCodes().count))
for countryCode : AnyObject in NSLocale.ISOCountryCodes() {
  let dictionary : NSDictionary = NSDictionary(object:countryCode, forKey:NSLocaleCountryCode)
  let identifier : NSString     = NSLocale.localeIdentifierFromComponents(dictionary)
  // next line - fatal error: Can't unwrap Optional.None
  let country    : NSString     = 
    NSLocale.currentLocale().displayNameForKey(NSLocaleIdentifier, value: identifier)
  countries.addObject(country)
}
println(countries)

什么是“致命错误：无法解包Optional.None”错误是什么意思？我一直在尝试和搜索它，但我还没有找到解决方案：/

百万谢谢:)

Answer 1

这一行是一个可选字符串

  let identifier : NSString = NSLocale.localeIdentifierFromComponents(dictionary)

用。。。来代替

  let identifier : NSString? = NSLocale.localeIdentifierFromComponents(dictionary)

然后

if identifier {
  let country : NSString = 
     NSLocale.currentLocale().displayNameForKey(NSLocaleIdentifier, value: identifier!)   
 countries.addObject(country)
}

Answer 2

尝试这个：D

var countries : String[] = Array()
for countryCodes : AnyObject in NSLocale.ISOCountryCodes() {
        let dictionary : NSDictionary = NSDictionary(object:countryCodes, forKey:NSLocaleCountryCode)
        let identifier : NSString? = NSLocale.localeIdentifierFromComponents(dictionary)
        if identifier {
            let country : NSString = NSLocale.currentLocale().displayNameForKey(NSLocaleIdentifier, value: identifier!)
            countries.append(country)
        }
    }
println(countries)

我认为这一个代码可以帮助您获得国家列表：D

Answer 3

我和你面临同样的问题，这是我的代码

for countryCodes : AnyObject in NSLocale.ISOCountryCodes() {
    let dictionary : Dictionary = [NSLocaleCountryCode: countryCodes]
    let identifier : String? = NSLocale.localeIdentifierFromComponents(dictionary)
    if let id = identifier {
        let country : String = NSLocale(localeIdentifier: "en_GB").displayNameForKey(NSLocaleIdentifier, value: id)
        countries.append(country)
    }
}

或者从NSLocale.currentLocale()改为NSLocale(localeIdentifier: "en_GB")

Answer 4

对于swift3

let identifier = Locale.identifier(fromComponents: [NSLocale.Key.countryCode.rawValue:countryCode])

Answer 5

试试这个：

（编辑）使用Locale而不是NSLocale

func getCountriesList()->[String]{
    var countries = [String]()
    for code in Locale.isoRegionCodes {
        let id = Locale.identifier(fromComponents: [NSLocale.Key.countryCode.rawValue: code])
        if let name = Locale(identifier: id).localizedString(forRegionCode: code) {
            countries.append(name)
        }
    }
    return countries
}