隐藏在 Swift TextField 中的部分文本

Question

我使用像 (555( 555-5555 这样的掩码，但我也希望它看起来像 (555( 5 ** - ****。在输入文本时，我可以做些什么来像这样屏蔽用户？

掩码功能：

func applyPatternOnNumbers(pattern: String, replacmentCharacter: Character) -> String {
var pureNumber = self.replacingOccurrences( of: "[^0-9]", with: "", options: .regularExpression)
for index in 0 ..< pattern.count {
guard index < pureNumber.count else { return pureNumber }
let stringIndex = String.Index(encodedOffset: index)
let patternCharacter = pattern[stringIndex]
guard patternCharacter != replacmentCharacter else { continue }
pureNumber.insert(patternCharacter, at: stringIndex)
}
return pureNumber
}

用法：

sender.text = textString.applyPatternOnNumbers(pattern: "(###) ###-####", replacmentCharacter: "#")

Answer 1

您可以在String上创建一个扩展名，以屏蔽除国家/地区代码号(圆括号之间的任何数字(之外的所有数字。请注意，此功能肯定会有一些性能改进，但我希望它至少可以帮助您入门：

extension String {
func masked(replacementCharacter: Character = "*") -> String {
let regex = "\(.*?\)"
let ranges = self.ranges(pattern: regex)
func isContained(_ index: Int) -> Bool {
for range in ranges {
if index > range.location && index < range.location + range.length - 1 {
return true
}
}
return false
}
var maskedString = String()
for (index, character) in self.enumerated() {
if isContained(index) {
maskedString.append(character)
} else {
if String(character).isDigit {
maskedString.append(replacementCharacter)
} else {
maskedString.append(character)
}
}
}
return maskedString
}
}

这些是我在上面的代码中使用的一些扩展：

extension String {
var isDigit: Bool {
CharacterSet.decimalDigits.isSuperset(of: CharacterSet(charactersIn: self))
}
func ranges(pattern: String) -> [NSRange] {
let regex = try! NSRegularExpression(pattern: pattern)
return regex.matches(in: self, options: [], range: NSRange(location: 0, length: self.count)).map { $0.range }
}
subscript (bounds: CountableClosedRange<Int>) -> String {
let start = index(startIndex, offsetBy: bounds.lowerBound)
let end = index(startIndex, offsetBy: bounds.upperBound)
return String(self[start...end])
}
subscript (bounds: CountableRange<Int>) -> String {
let start = index(startIndex, offsetBy: bounds.lowerBound)
let end = index(startIndex, offsetBy: bounds.upperBound)
return String(self[start..<end])
}
}

如果您只想屏蔽字符串中的任何数字(甚至是括号内的数字(，则可以简化为：

extension String {
func masked(replacementCharacter: Character = "*") -> String {
var maskedString = String()
for character in self {
if String(character).isDigit {
maskedString.append(replacementCharacter)
} else {
maskedString.append(character)
}
}
return maskedString
}
}

然后你可以简单地使用它，就像这样：

let input = "[phone]"
let output = input.masked()
// Prints (123) ***-****