对于 Swift 3 。在文本字段上输入货币格式（从右到左）
override func viewDidLoad() { super.viewDidLoad() textField.addTarget(self, action: #selector(myTextFieldDidChange), for: .editingChanged)}func myTextFieldDidChange(_ textField: UITextField) { if let amountString = textField.text?.currencyInputFormatting() { textField.text = amountString }}extension String { // formatting text for currency textField func currencyInputFormatting() -> String { var number: NSNumber! let formatter = NumberFormatter() formatter.numberStyle = .currencyAccounting formatter.currencySymbol = "$" formatter.maximumFractionDigits = 2 formatter.minimumFractionDigits = 2 var amountWithPrefix = self // remove from String: "$", ".", "," let regex = try! NSRegularexpression(pattern: "[^0-9]", options: .caseInsensitive) amountWithPrefix = regex.stringByReplacingMatches(in: amountWithPrefix, options: NSRegularexpression.MatchingOptions(rawValue: 0), range: NSMakeRange(0, self.characters.count), withTemplate: "") let double = (amountWithPrefix as NSString).doublevalue number = NSNumber(value: (double / 100)) // if first number is 0 or all numbers were deleted guard number != 0 as NSNumber else { return "" } return formatter.string(from: number)! }}
