如何使用Swift（macOS）获取对应货币代码的货币符号。
示例：
我的代码：
var formatter = NSNumberFormatter()
formatter.currencySymbol = getSymbol(currencyCode)
formatter.numberStyle = NSNumberFormatterStyle.CurrencyStyle
let number = NSNumber(double: (amount as NSString).doubleValue)
let amountWithSymbol = formatter.stringFromNumber(number)!
getSymbol(_ currencyCode: String) -> String
还有... 是否有更好的方法吗？
有点晚了，但这是我用来获取货币符号$而不是US$等的解决方案。
/*
* Bear in mind not every currency have a corresponding symbol.
*
* EXAMPLE TABLE
*
* currency code | Country & Currency | Currency Symbol
*
* BGN | Bulgarian lev | лв
* HRK | Croatian Kuna | kn
* CZK | Czech Koruna | Kč
* EUR | EU Euro | €
* USD | US Dollar | $
* GBP | British Pound | £
*/
func getSymbol(forCurrencyCode code: String) -> String? {
let locale = NSLocale(localeIdentifier: code)
return locale.displayNameForKey(NSLocaleCurrencySymbol, value: code)
}
基本上，这将从您的货币代码创建NSLocale并获取货币的显示属性。在结果匹配货币代码（例如SEK）的情况下，它将通过从货币代码中删除最后一个字符并添加“_en”来形成SE_en，创建新的特定于国家/地区的语言环境。然后再次尝试获取货币符号。
Swift 3＆4
func getSymbol(forCurrencyCode code: String) -> String? {
let locale = NSLocale(localeIdentifier: code)
if locale.displayName(forKey: .currencySymbol, value: code) == code {
let newlocale = NSLocale(localeIdentifier: code.dropLast() + "_en")
return newlocale.displayName(forKey: .currencySymbol, value: code)
}
return locale.displayName(forKey: .currencySymbol, value: code)
}
答案可能会晚一些，但希望这有助于澄清根本原因。
CAD变成CA$的原因可能是因为NSLocale在查找第一个匹配的货币代码时，对于CAD而言，以下是按照NSLocale.availableLocaleIdentifiers顺序排序的匹配的localeIdentifiers：
1. Optional("CA$") Optional("CA") iu_CA
2. Optional("$") Optional("CA") fr_CA
3. Optional("$") Optional("CA") en_CA
iu_CA是伊努克提图特语，但我不确定为什么它被列为CA$，但我希望重点是清楚的。
同样，在CNY（人民币）中：
1. Optional("CN¥") Optional("CN") en_CN
2. Optional("¥") Optional("CN") yue_CN
3. Optional("¥") Optional("CN") bo_CN
4. Optional("¥") Optional("CN") zh_CN
5. Optional("￥") Optional("CN") ug_CN
6. Optional("¥") Optional("CN") ii_CN
1. Optional("CHF") Optional("LI") gsw_LI
2. Optional("CHF") Optional("CH") de_CH
...
9. Optional("CHF") Optional("CH") en_CH
10. Optional("CHF") Optional("CH") it_CH
虽然应用程序各不相同，但这是我为自己的应用程序采取的步骤:
实现
func getSymbolForCurrencyCode(code: String) -> String {
var candidates: [String] = []
let locales: [String] = NSLocale.availableLocaleIdentifiers
for localeID in locales {
guard let symbol = findMatchingSymbol(localeID: localeID, currencyCode: code) else {
continue
}
if symbol.count == 1 {
return symbol
}
candidates.append(symbol)
}
let sorted = sortAscByLength(list: candidates)
if sorted.count < 1 {
return ""
}
return sorted[0]
}
func findMatchingSymbol(localeID: String, currencyCode: String) -> String? {
let locale = Locale(identifier: localeID as String)
guard let code = locale.currencyCode else {
return nil
}
if code != currencyCode {
return nil
}
guard let symbol = locale.currencySymbol else {
return nil
}
return symbol
}
func sortAscByLength(list: [String]) -> [String] {
return list.sorted(by: { $0.count < $1.count })
}
使用方法
let usd = getSymbolForCurrencyCode(code: "USD")
let jpy = getSymbolForCurrencyCode(code: "JPY")
let cny = getSymbolForCurrencyCode(code: "CNY")
let cad = getSymbolForCurrencyCode(code: "CAD")
let uah = getSymbolForCurrencyCode(code: "UAH")
let krw = getSymbolForCurrencyCode(code: "KRW")
let zar = getSymbolForCurrencyCode(code: "ZAR")
let chf = getSymbolForCurrencyCode(code: "CHF")
let all = [usd, jpy, cny, cad, uah, krw, zar, chf]
(lldb) po all
▿ 8 elements
- 0 : "$"
- 1 : "¥"
- 2 : "¥"
- 3 : "$"
- 4 : "₴"
- 5 : "₩"
- 6 : "R"
- 7 : "CHF"
问题
guard let symbol = locale.currencySymbol else { return nil }，而 sortAscByLength 是 n log n，但我们只需要最低字符长度的一个，所以我们可能可以删除它，并在循环中将具有最低字符长度的符号保留在变量中。我一定是累了... - Taku正确的做法是让框架为您提供信息。
您可以使用NSLocale中的一个晦涩的类方法localeIdentifierFromComponents()检索该信息。该方法将使用定义区域设置的各种属性的字典作为参数，然后返回一个标识符，您可以使用它来实际构建NSLocale实例。一旦您拥有了NSLocale，您就可以询问它的CurrencySymbol，如下所示：
let currencyCode = "CAD"
let localeComponents = [NSLocaleCurrencyCode: currencyCode]
let localeIdentifier = NSLocale.localeIdentifierFromComponents(localeComponents)
let locale = NSLocale(localeIdentifier: localeIdentifier)
let currencySymbol = locale.objectForKey(NSLocaleCurrencySymbol) as! String
// currencySymbol is "CA$"
我将这里所有的建议结合并改进，以便未来读者（您）可以轻松复制/粘贴使用。
它拥有自己的本地缓存，不区分大小写，并且具有扩展方法以提供String的链接。适用于Swift 4/5。
如何使用：
"USD".currencySymbol //returns "$"
//OR
Currency.shared.findSymbol(currencyCode: "TRY") //returns "₺"
测试：
XCTAssertEqual("$", "USD".currencySymbol)
XCTAssertEqual("₺", "TRY".currencySymbol)
XCTAssertEqual("€", "EUR".currencySymbol)
XCTAssertEqual("", "ASDF".currencySymbol)
代码：
class Currency {
static let shared: Currency = Currency()
private var cache: [String:String] = [:]
func findSymbol(currencyCode:String) -> String {
if let hit = cache[currencyCode] { return hit }
guard currencyCode.count < 4 else { return "" }
let symbol = findSymbolBy(currencyCode)
cache[currencyCode] = symbol
return symbol
}
private func findSymbolBy(_ currencyCode: String) -> String {
var candidates: [String] = []
let locales = NSLocale.availableLocaleIdentifiers
for localeId in locales {
guard let symbol = findSymbolBy(localeId, currencyCode) else { continue }
if symbol.count == 1 { return symbol }
candidates.append(symbol)
}
return candidates.sorted(by: { $0.count < $1.count }).first ?? ""
}
private func findSymbolBy(_ localeId: String, _ currencyCode: String) -> String? {
let locale = Locale(identifier: localeId)
return currencyCode.caseInsensitiveCompare(locale.currencyCode ?? "") == .orderedSame
? locale.currencySymbol : nil
}
}
extension String {
var currencySymbol: String { return Currency.shared.findSymbol(currencyCode: self) }
}
let locale = Locale.current // currency symbol from current location
//let locale = Locale(identifier: "fr_FR") // or you could specify the locale e.g fr_FR, en_US etc
let currencySymbol = locale.currencySymbol!
print("\(currencySymbol)")
我建议采用更快速、更方便的方法。您可以获取特定货币的所有可能符号：
Currency.currency(for: "USD")! // Currency(code: "USD", symbols: ["US$", "USD", "$"])
Currency.currency(for: "CAD")! // Currency(code: "USD", symbols: ["$", "CA$"])
或者获得最短的符号。通常这就是大家想要的：
Currency.currency(for: "CAD")!.shortestSymbol // "$"
现在来谈一下速度问题。首次调用此方法需要线性时间，与语言环境数量和代码数量成比例。对于任何代码的每个后续调用都是在常量时间内执行的。因此，如果您正在实现一个 CurrencyPickerViewController 或类似的东西，那么这个解决方案是最优的。
此外，这个解决方案还有一个优点。由于全局常量和变量总是懒计算的，如果您从未调用过某个获得货币信息的方法，那么缓存不会占用任何内存。
struct Currency {
/// Returns the currency code. For example USD or EUD
let code: String
/// Returns currency symbols. For example ["USD", "US$", "$"] for USD, ["RUB", "₽"] for RUB or ["₴", "UAH"] for UAH
let symbols: [String]
/// Returns shortest currency symbols. For example "$" for USD or "₽" for RUB
var shortestSymbol: String {
return symbols.min { $0.count < $1.count } ?? ""
}
/// Returns information about a currency by its code.
static func currency(for code: String) -> Currency? {
return cache[code]
}
// Global constants and variables are always computed lazily, in a similar manner to Lazy Stored Properties.
static fileprivate var cache: [String: Currency] = { () -> [String: Currency] in
var mapCurrencyCode2Symbols: [String: Set<String>] = [:]
let currencyCodes = Set(Locale.commonISOCurrencyCodes)
for localeId in Locale.availableIdentifiers {
let locale = Locale(identifier: localeId)
guard let currencyCode = locale.currencyCode, let currencySymbol = locale.currencySymbol else {
continue
}
if currencyCode.contains(currencyCode) {
mapCurrencyCode2Symbols[currencyCode, default: []].insert(currencySymbol)
}
}
var mapCurrencyCode2Currency: [String: Currency] = [:]
for (code, symbols) in mapCurrencyCode2Symbols {
mapCurrencyCode2Currency[code] = Currency(code: code, symbols: Array(symbols))
}
return mapCurrencyCode2Currency
}()
}
要查看此功能在所有代码中的工作原理，您可以使用以下代码：
for code in Locale.commonISOCurrencyCodes {
guard let currency = Currency.currency(for: code) else {
// Three codes have no symbol. This is CUC, LSL and VEF
print("Missing symbols for code \(code)")
continue
}
print(currency)
}
SWIFT4
//converting USD to $a and GBP to £
viewDidLoad()
{
print(getSymbolForCurrencyCode(code: "USD")!) // prints $
print(getSymbolForCurrencyCode(code: "GBP")!) //prints £
}
func getSymbolForCurrencyCode(code: String) -> String?
{
let locale = NSLocale(localeIdentifier: code)
return locale.displayName(forKey: NSLocale.Key.currencySymbol, value: code)
}
- (NSLocale *)localeFromCurrencyCode:(NSString *)currencyCode {
NSLocale *locale = [NSLocale currentLocale];
if (![locale.currencyCode isEqualToString:currencyCode]) {
NSDictionary *localeInfo = @{NSLocaleCurrencyCode:currencyCode};
locale = [[NSLocale alloc] initWithLocaleIdentifier:[NSLocale localeIdentifierFromComponents:localeInfo]];
}
return locale;
}
Swift
func locale(from currencyCode: String) -> Locale {
var locale = Locale.current
if (locale.currencyCode != currencyCode) {
let identifier = NSLocale.localeIdentifier(fromComponents: [NSLocale.Key.currencyCode.rawValue: currencyCode])
locale = NSLocale(localeIdentifier: identifier) as Locale
}
return locale;
}
Swift 4版本的Pancho答案，由于现在String.characters已经弃用。
我们可以简单地在String上应用dropLast()。
func getCurrencySymbol(from currencyCode: String) -> String? {
let locale = NSLocale(localeIdentifier: currencyCode)
if locale.displayName(forKey: .currencySymbol, value: currencyCode) == currencyCode {
let newlocale = NSLocale(localeIdentifier: currencyCode.dropLast() + "_en")
return newlocale.displayName(forKey: .currencySymbol, value: currencyCode)
}
return locale.displayName(forKey: .currencySymbol, value: currencyCode)
}
extension Locale {
static func locale(from currencyIdentifier: String) -> Locale? {
let allLocales = Locale.availableIdentifiers.map({ Locale.init(identifier: $0) })
return allLocales.filter({ $0.currencyCode == currencyIdentifier }).first
}
}
NSLocale（localeIdentifier :)的参数应该是一个本地标识符，通常由ISO 639-1语言代码（例如英语为en）和ISO 3166-2区域代码（例如美国为US）组成。但是在上面的代码中将货币代码传递给了该函数。这很奇怪。 - rayx