我越来越无法使用字符串类型的参数调用计数 [重复]

Posted 2023-02-23

【中文标题】我越来越无法使用字符串类型的参数调用计数 [重复]

【英文标题】：i am getting cannot invoke count with an argument of string type [duplicate]

【发布时间】：2016-06-23 08:56:48

【问题描述】：

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool 
            var result = true
            let prospectiveText = (textField.text as NSString).stringByReplacingCharactersInRange(range, withString: string)

            if textField == textfield4 
                if count(string) > 0 
                    let disallowedCharacterSet = NSCharacterSet(charactersInString: "0123456789.").invertedSet
                    let replacementStringIsLegal = string.rangeOfCharacterFromSet(disallowedCharacterSet) == nil

                    let resultingStringLengthIsLegal = count(prospectiveText) <= 9

                    let scanner = NSScanner(string: prospectiveText)
                    let resultingTextIsNumeric = scanner.scanDecimal(nil) && scanner.atEnd

                    result = replacementStringIsLegal &&
                        resultingStringLengthIsLegal &&
                    resultingTextIsNumeric
                
            
            return result
        

【参考方案1】：

使用

prospectiveText.characters.count

而不是

count(prospectiveText)

【讨论】：

prospectiveText 意义上的