问题限制小数长度

Question

我在所有UITexField:中使用的代码最多限制为1个十进制数

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
    let computationString = (textField.text! as NSString).stringByReplacingCharactersInRange(range, withString: string)

    let arrayOfSubStrings = computationString.componentsSeparatedByString(",")

    if (arrayOfSubStrings.count == 1 && computationString.characters.count > 2) {
        return false
    } else if arrayOfSubStrings.count == 2 {
        let stringPostDecimal = arrayOfSubStrings[1]
        return stringPostDecimal.characters.count <= 1
    }

    return true
}

但我只知道有两种类型的小数点填充符：带点和带逗号。

例如，我的iOS模拟器使用句点，我的iPhone使用逗号。那么，我该如何解决这个问题，同时阻止它们呢？

Answer 1

有一种方法componentsSeparatedByCharactersInSet可以考虑多个分离字符

let commaDotCharacterSet = NSCharacterSet(charactersInString: ",.")
let arrayOfSubStrings = computationString.componentsSeparatedByCharactersInSet(commaDotCharacterSet)

或者还包括当前区域设置的十进制分隔符

let localeDecimalSeparator = NSLocale.currentLocale().objectForKey(NSLocaleDecimalSeparator) as! String
let commaDotLocaleSeparatorCharacterSet = NSCharacterSet(charactersInString: ",." + localeDecimalSeparator)
let arrayOfSubStrings = computationString.componentsSeparatedByCharactersInSet(commaDotLocaleSeparatorCharacterSet)

Answer 2

试试这个。

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
    let computationString = (textField.text! as NSString).stringByReplacingCharactersInRange(range, withString: string)
    let arrayOfSubStrings = computationString.computationString.componentsSeparatedByCharactersInSet(NSCharacterSet(charactersInString: ".,"))
    if (arrayOfSubStrings.count == 1 && computationString.characters.count > 2) {
        return false
    } else if arrayOfSubStrings.count == 2 {
        let stringPostDecimal = arrayOfSubStrings[1]
        return stringPostDecimal.characters.count <= 1
    }
    return true
}