输入时在Swift中的文本字段中格式化货币

Question

我正在尝试在用户输入时在Swift的文本字段中格式化货币输入.

到目前为止,我只能在用户完成输入时成功格式化:

@IBAction func editingEnded(sender: AnyObject) {

    let formatter = NSNumberFormatter()
    formatter.numberStyle = NSNumberFormatterStyle.CurrencyStyle
    formatter.locale = NSLocale(localeIdentifier: "en_US")
    var numberFromField = NSString(string: textField.text).doubleValue

    textField.text = formatter.stringFromNumber(numberFromField)
}

但是,我想在用户输入货币时格式化货币.当我尝试在TextField操作"编辑已更改"或"值已更改"时执行此操作时,我只能输入1个数字(如果我输入8,则变为$ 8.00)但是一旦我输入第二个数字,一切都会达到0.00美元而我除此之外不能进一步进入.

有什么建议？我觉得这应该是一个简单的修复,但我不能完全理解它.

Answer 1

我今天早些时候修改了这个功能.适用于"en_US"和"fr_FR".但是,对于"ja_JP",除以100除以创建小数是一个问题.您需要有一个switch或if/else语句,用于分隔带小数的货币和用格式化程序格式化的货币.但我认为这会让你进入你想成为的空间.

import UIKit

class ViewController: UIViewController, UITextFieldDelegate {

    @IBOutlet weak var textField: UITextField!
    var currentString = ""

    override func viewDidLoad() {
        super.viewDidLoad()

        self.textField.delegate = self
    }

    //Textfield delegates
    func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool { // return NO to not change text

        switch string {
        case "0","1","2","3","4","5","6","7","8","9":
            currentString += string
            println(currentString)
            formatCurrency(string: currentString)
        default:
            var array = Array(string)
            var currentStringArray = Array(currentString)
            if array.count == 0 && currentStringArray.count != 0 {
                currentStringArray.removeLast()
                currentString = ""
                for character in currentStringArray {
                    currentString += String(character)
                }
                formatCurrency(string: currentString)
            }
        }
        return false
    }

    func formatCurrency(#string: String) {
        println("format \(string)")
        let formatter = NSNumberFormatter()
        formatter.numberStyle = NSNumberFormatterStyle.CurrencyStyle
        formatter.locale = NSLocale(localeIdentifier: "en_US")
        var numberFromField = (NSString(string: currentString).doubleValue)/100
        textField.text = formatter.stringFromNumber(numberFromField)
        println(textField.text )
    }
}

Answer 2

这适用于我使用NSNumberFormatter ...

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {

    // Construct the text that will be in the field if this change is accepted
    var oldText = textField.text as NSString
    var newText = oldText.stringByReplacingCharactersInRange(range, withString: string) as NSString!
    var newTextString = String(newText)

    let digits = NSCharacterSet.decimalDigitCharacterSet()
    var digitText = ""
    for c in newTextString.unicodeScalars {
        if digits.longCharacterIsMember(c.value) {
            digitText.append(c)
        }
    }

    let formatter = NSNumberFormatter()
    formatter.numberStyle = NSNumberFormatterStyle.CurrencyStyle
    formatter.locale = NSLocale(localeIdentifier: "en_US")
    var numberFromField = (NSString(string: digitText).doubleValue)/100
    newText = formatter.stringFromNumber(numberFromField)

    textField.text = newText

    return false
}

Answer 3

基于@Robert回答.针对Swift 2.0进行了更新

//Textfield delegates
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool { // return NO to not change text

    switch string {
    case "0","1","2","3","4","5","6","7","8","9":
        currentString += string
        formatCurrency(currentString)
    default:
        if string.characters.count == 0 && currentString.characters.count != 0 {
            currentString = String(currentString.characters.dropLast())
            formatCurrency(currentString)
        }
    }
    return false
}

func formatCurrency(string: String) {
    print("format \(string)")
    let formatter = NSNumberFormatter()
    formatter.numberStyle = NSNumberFormatterStyle.CurrencyStyle
    formatter.locale = NSLocale(localeIdentifier: "en_US")
    let numberFromField = (NSString(string: currentString).doubleValue)/100
    self.amountField.text = formatter.stringFromNumber(numberFromField)
    print(self.amountField.text )
}