[ Swift ] TextField 가격 입력에 따라 쉼표 찍기( 지울때도 쉼표 옮겨주기 ! )

    func textFieldDidChangeSelection(_ textField: UITextField) {
        let formatter = NumberFormatter()
        formatter.numberStyle = .decimal
        formatter.locale = .current
        formatter.maximumFractionDigits = 0
        
        //textField.text = formatter.number(from: self.numInput!)
        print("numInput: \(self.numInput)")
        if self.inputDeleteFlag {
            if let formattedNumber = formatter.number(from:     String(self.numInput!)),
               let formattedString = formatter.string(from: formattedNumber){
                print("FFFFFFFF : \(formattedString)")
                textField.text = formattedString
            }
        }
        print("TEXTFIELD DID CHANGE SELECTION : \(textField.text!)")
    }


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

        self.isComparable = false
        
        let formatter = NumberFormatter()
        formatter.numberStyle = .decimal
        formatter.locale = Locale.current
        formatter.maximumFractionDigits = 0//소숫점은 없어요
        
        if (string.first == "0" && textField.text == "") {
            print("0은 앞에 올 수 없어")
            return false
        } else {
            
            if (!(minTextField.text!.isEmpty) && !(maxTextField.text!.isEmpty)) {
                self.isComparable = true
            } else {
                self.isComparable = false
            }


            if let removeAllSeperator = textField.text?.replacingOccurrences(of: formatter.groupingSeparator, with: "") {
                
                //print("RemoveAllSeperator : \(removeAllSeperator)")//그냥 쉼표없는 쌩값임 ex) 123456
                
                var beforeFormattedString = removeAllSeperator + string
                //쌓이는값 + 현재누른값(string) = beforeFormattedString
                print("\n\n removeAllSeperatoe : \(removeAllSeperator), string : \(string) \n beforeFormattedString : \(beforeFormattedString)\n" )
                
                print("formatter.number(from: string) : \(formatter.number(from: string))")
                
                if formatter.number(from: string) != nil {//누른 값이 있다면!
                    
                    self.inputDeleteFlag = false
                    if let formattedNumber = formatter.number(from: beforeFormattedString),
                       let formattedString = formatter.string(from: formattedNumber) {
                        
                        print("formattedNumber : \(formattedNumber)")
                        print("formattedString : \(formattedString)")
                        
                        textField.text = formattedString
                        return false
                    }
                } else {//지운다면!
                    self.inputDeleteFlag = true
                    self.numInput = String(beforeFormattedString.dropLast())

                    
                }
                
            
    
            }
            
            
            return true
        }
    }