Question

我正在尝试在两个textFields上添加字符限制限制。我也将十进制输入限制为只有一个十进制，似乎工作正常。我的角色限制导致许多错误。这是最好的方法吗？

        func textField(_ textField: UITextField,shouldChangeCharactersIn range: NSRange,replacementString string: String) -> Bool
        {
            let characterLimit = 8
            let countdotsStockPrice = (stockPrice.text?.components(separatedBy: ".").count)! - 1
            let countdotsCapitalInvested = (capitalInvested.text?.components(separatedBy: ".").count)! - 1

            //TextField1: stockPrice.text
            let currentString: NSString = (stockPrice.text ?? "") as NSString
            let newString = currentString.replacingCharacters(in: range, with: string)

                 //TextField2: capitalInvested.text
                let currentStringCapital: NSString = (capitalInvested.text ?? "") as NSString
                let newStringCapital = currentStringCapital.replacingCharacters(in: range, with: string)



            if textField == stockPrice {

                if (newString.characters.count >= characterLimit) {
                    stockPrice.deleteBackward()
                }

                if countdotsStockPrice > 0 && string == "." { return false} else {return true}

            } else if textField == capitalInvested {



                if (newStringCapital.characters.count >= characterLimit) {
                    capitalInvested.deleteBackward()
                }


                if countdotsCapitalInvested > 0 && string == "." { return false} else {return true}

            }

            if textField == stockPrice || textField == capitalInvested {



            }
            return true
        }

Answer 1

检查一下，

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

    // check decimal restriction
    let replacementStringIsLegal = string.rangeOfCharacter(from: CharacterSet(charactersIn:"0123456789")) == nil

    if !replacementStringIsLegal {
        return false
    }
    let nsString = textField.text as NSString?
    let newString = nsString!.replacingCharacters(in: range, with: string)

    // check maximum length
    if newString.characters.count > 4 {
        return false
    }
    return true

}

希望这会对你有所帮助。

Answer 2

您可以这样存档：

private let decimalSeparator = "."

func isFractionalPartValid(in string: String) -> Bool {
    let maxFractionalPartLength = 1
    guard let separator = decimalSeparator.characters.first,
        let comaIndex = string.characters.index(of: separator),
        string.distance(from: comaIndex, to: string.endIndex) > maxFractionalPartLength + 1 else {
            return true
    }
    return false
}

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    let set = CharacterSet.decimalDigits.union(CharacterSet(charactersIn: decimalSeparator)).inverted
    let maxLength = 8
    let currentString: NSString = (textField.text ?? "") as NSString
    let newString = currentString.replacingCharacters(in: range, with: string)

    if newString.characters.count > maxLength || newString.rangeOfCharacter(from: set) != nil {
        return false
    }
//Below is not required but possibly you need it ;)
    if newString.characters.count == maxLength && newString.characters.last == decimalSeparator.characters.first {
        return false
    }

    return isFractionalPartValid(in: newString)
}

但老实说，我认为你应该把这个逻辑转移到另一个对象

带有小数和长度的Swift TextField限制

2 个答案: