如何在swift中输入信用卡(xxxx-xxxx-xxxx)文本

Question

我正在尝试使用以下代码创建信用卡类型文本,但无法做到这一点,有什么办法吗？

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

    formatter.groupingSize = 4
    formatter.groupingSeparator = "-"
    formatter.usesGroupingSeparator = true

    print("txtCardNumber \(txtCardNumber.text)")
}

Answer 1

这是快速快速3版本的答案.此逻辑实现了带空格的简单16位信用卡格式.

第1步:为信用卡文本字段创建操作

self.txtFieldCreditCardNumber.addTarget(self, action: #selector(didChangeText(textField:)), for: .editingChanged)

第2步:从将执行格式化的textfield选择器方法中调用方法

@objc func didChangeText(textField:UITextField) {
    textField.text = self.modifyCreditCardString(creditCardString: textField.text!)
}

第3步:实现方法"modifyCreditCardString"

func modifyCreditCardString(creditCardString : String) -> String {
     let trimmedString = creditCardString.components(separatedBy: .whitespaces).joined()

     let arrOfCharacters = Array(trimmedString)
     var modifiedCreditCardString = ""

     if(arrOfCharacters.count > 0) {
         for i in 0...arrOfCharacters.count-1 {
             modifiedCreditCardString.append(arrOfCharacters[i])
             if((i+1) % 4 == 0 && i+1 != arrOfCharacters.count){
                 modifiedCreditCardString.append(" ")
             }
         }
     }
     return modifiedCreditCardString
 }

第4步:实现UITextField的委托

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
     let newLength = (textField.text ?? "").count + string.count - range.length
     if(textField == txtFieldCreditCardNumber) {
         return newLength <= 19
     }
     return true
}

就这些.谢谢