在Swift中使用NSNumberFormatter进行货币争夺

Question

我正在创建一个预算应用程序,允许用户输入他们的预算和交易.我需要允许用户从单独的文本字段输入便士和磅数,并且需要将它们与货币符号一起格式化.我现在工作得很好,但是想把它本地化,因为目前它只适用于GBP.我一直在努力将NSNumberFormatter的例子从Objective C转换为Swift.

我的第一个问题是我需要将输入字段的占位符设置为特定于用户位置.例如.英镑和便士,美元和美分等......

第二个问题是需要格式化在诸如10216和32的每个文本字段中输入的值,并且需要添加特定于用户位置的货币符号.所以这将是10,216.32英镑或10,216.32美元等...

另外,我需要在计算中使用格式化数字的结果.那么如何在不遇到货币符号问题的情况下解决问题呢？

任何帮助将非常感激.

Answer 1

这是一个关于如何在Swift 3上使用它的示例.(编辑:也适用于Swift 4)

let price = 123.436 as NSNumber

let formatter = NumberFormatter()
formatter.numberStyle = .currency
// formatter.locale = NSLocale.currentLocale() // This is the default
// In Swift 4, this ^ has been renamed to simply NSLocale.current
formatter.string(from: price) // "$123.44"

formatter.locale = Locale(identifier: "es_CL")
formatter.string(from: price) // $123"

formatter.locale = Locale(identifier: "es_ES")
formatter.string(from: price) // "123,44 €"

这是关于如何在Swift 2上使用它的旧例子.

let price = 123.436

let formatter = NSNumberFormatter()
formatter.numberStyle = .CurrencyStyle
// formatter.locale = NSLocale.currentLocale() // This is the default
formatter.stringFromNumber(price) // "$123.44"

formatter.locale = NSLocale(localeIdentifier: "es_CL")
formatter.stringFromNumber(price) // $123"

formatter.locale = NSLocale(localeIdentifier: "es_ES")
formatter.stringFromNumber(price) // "123,44 €"

Answer 2

斯威夫特3:

如果您正在寻找能够为您提供的解决方案:

• "5"="5美元"
• "5.0"="5美元"
• "5.00"="$ 5"
• "5.5"="5.50美元"
• "5.50"="$ 5.50"
• "5.55"="5.55美元"
• "5.234234"="5.23"

请使用以下内容:

func cleanDollars(_ value: String?) -> String {
    guard value != nil else { return "$0.00" }
    let doubleValue = Double(value!) ?? 0.0
    let formatter = NumberFormatter()
    formatter.currencyCode = "USD"
    formatter.currencySymbol = "$"
    formatter.minimumFractionDigits = (value!.contains(".00")) ? 0 : 2
    formatter.maximumFractionDigits = 2
    formatter.numberStyle = .currencyAccounting
    return formatter.string(from: NSNumber(value: doubleValue)) ?? "$\(doubleValue)"
}

Answer 3

我已经实现了@NiñoScript提供的解决方案作为扩展:

延期

// Create a string with currency formatting based on the device locale
//
extension Float {
    var asLocaleCurrency:String {
        var formatter = NSNumberFormatter()
        formatter.numberStyle = .CurrencyStyle
        formatter.locale = NSLocale.currentLocale()
        return formatter.stringFromNumber(self)!
    }
}

用法:

let amount = 100.07
let amountString = amount.asLocaleCurrency
print(amount.asLocaleCurrency())
// prints: "$100.07"

斯威夫特3

    extension Float {
    var asLocaleCurrency:String {
        var formatter = NumberFormatter()
        formatter.numberStyle = .currency
        formatter.locale = Locale.current
        return formatter.string(from: self)!
    }
}

Answer 4

Xcode 9•Swift 4

extension Locale {
    static let br = Locale(identifier: "pt_BR")
    static let us = Locale(identifier: "en_US")
    static let uk = Locale(identifier: "en_UK")
}

extension NumberFormatter {
    convenience init(style: Style, locale: Locale = .current) {
        self.init()
        self.locale = locale
        numberStyle = style
    }
}

extension Formatter {
    static let currency = NumberFormatter(style: .currency)
    static let currencyUS = NumberFormatter(style: .currency, locale: .us)
    static let currencyBR = NumberFormatter(style: .currency, locale: .br)
}

extension Numeric {
    var currency: String { Formatter.currency.string(for: self) ?? "" }
    var currencyUS: String { Formatter.currencyUS.string(for: self) ?? "" }
    var currencyBR: String { Formatter.currencyBR.string(for: self) ?? "" }
}

let price = 1.99

print(Formatter.currency.locale)  // "en_US (current)\n"
print(price.currency)             // "$1.99\n"

Formatter.currency.locale = .br
print(price.currency)  // "R$1,99\n"

Formatter.currency.locale = .uk
print(price.currency)  // "£1.99\n"

print(price.currencyBR)  // "R$1,99\n"
print(price.currencyUS)  // "$1.99\n"

Answer 5

细节

xCode 9.2,Swift 4

解决方案1

import Foundation

class CurrencyFormatter {
    static var outputFormatter = CurrencyFormatter.create()
    class func create(locale: Locale = Locale.current,
                      groupingSeparator: String? = nil,
                      decimalSeparator: String? = nil,
                      style: NumberFormatter.Style = NumberFormatter.Style.currency) -> NumberFormatter {
        let outputFormatter = NumberFormatter()
        outputFormatter.locale = locale
        outputFormatter.decimalSeparator = decimalSeparator ?? locale.decimalSeparator
        outputFormatter.groupingSeparator = groupingSeparator ?? locale.groupingSeparator
        outputFormatter.numberStyle = style
        return outputFormatter
    }
}

extension Numeric {
    func toCurrency(formatter: NumberFormatter = CurrencyFormatter.outputFormatter) -> String? {
        guard let num = self as? NSNumber else { return nil }
        var formatedSting = formatter.string(from: num)
        guard let locale = formatter.locale else { return formatedSting }
        if let separator = formatter.groupingSeparator, let localeValue = locale.groupingSeparator {
            formatedSting = formatedSting?.replacingOccurrences(of: localeValue, with: separator)
        }
        if let separator = formatter.decimalSeparator, let localeValue = locale.decimalSeparator {
            formatedSting = formatedSting?.replacingOccurrences(of: localeValue, with: separator)
        }
        return formatedSting
    }
}

用法

let price = 12423.42
print(price.toCurrency() ?? "")

CurrencyFormatter.outputFormatter = CurrencyFormatter.create(style: .currencyISOCode)
print(price.toCurrency() ?? "nil")

CurrencyFormatter.outputFormatter = CurrencyFormatter.create(locale: Locale(identifier: "es_ES"))
print(price.toCurrency() ?? "nil")

CurrencyFormatter.outputFormatter = CurrencyFormatter.create(locale: Locale(identifier: "de_DE"), groupingSeparator: " ", style: .currencyISOCode)
print(price.toCurrency() ?? "nil")

CurrencyFormatter.outputFormatter = CurrencyFormatter.create(groupingSeparator: "_", decimalSeparator: ".", style: .currencyPlural)
print(price.toCurrency() ?? "nil")

let formatter = CurrencyFormatter.create(locale: Locale(identifier: "de_DE"), groupingSeparator: " ", decimalSeparator: ",", style: .currencyPlural)
print(price.toCurrency(formatter: formatter) ?? "nil")

结果

解决方案2

$12,423.42
USD12,423.42
12.423,42 €
12 423,42 EUR
12_423.42 US dollars
12 423,42 Euro

用法

import Foundation

class CurrencyFormatter {
    static var outputFormatter = CurrencyFormatter.create()
    class func create(locale: Locale = Locale.current,
                      groupingSeparator: String? = nil,
                      decimalSeparator: String? = nil,
                      style: NumberFormatter.Style = NumberFormatter.Style.currency) -> NumberFormatter {
        let outputFormatter = NumberFormatter()
        outputFormatter.locale = locale
        outputFormatter.decimalSeparator = decimalSeparator ?? locale.decimalSeparator
        outputFormatter.groupingSeparator = groupingSeparator ?? locale.groupingSeparator
        outputFormatter.numberStyle = style
        return outputFormatter
    }
}

extension Numeric {
    func toCurrency(formatter: NumberFormatter = CurrencyFormatter.outputFormatter) -> String? {
        guard let num = self as? NSNumber else { return nil }
        var formatedSting = formatter.string(from: num)
        guard let locale = formatter.locale else { return formatedSting }
        if let separator = formatter.groupingSeparator, let localeValue = locale.groupingSeparator {
            formatedSting = formatedSting?.replacingOccurrences(of: localeValue, with: separator)
        }
        if let separator = formatter.decimalSeparator, let localeValue = locale.decimalSeparator {
            formatedSting = formatedSting?.replacingOccurrences(of: localeValue, with: separator)
        }
        return formatedSting
    }
}