Question

我有一个UITextField，我想将字段中允许的最大输入值限制为1000 .eg（1-1000），如果textfield中的值超过1000，则textfield不应该将值设置为输入。我试过以下

func textField(_ textField: UITextField,shouldChangeCharactersIn range: NSRange,replacementString string: String) -> Bool
{
    var newString: String = textField.text.replacingCharacters(in: range, with: string)
    var characterSet = CharacterSet(charactersIn: "0123456789,.").inverted
    if (newString as NSString).rangeOfCharacter(from: characterSet).location != NSNotFound {
        return false
    }
    return Double(newString) ?? 0.0 < 1000
}

Answer 1

试试这个。希望这会有所帮助

 func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        guard let text = textField.text else { return true }
        let newLength = text.characters.count + string.characters.count - range.length
        return newLength <= 1001 
    }

Answer 2

尝试从textField中提取整数值，并检查它是否低于1000。

- (BOOL)textFieldShouldReturn:(UITextField *)textField
  {
      NSInteger inte = [textField.text intValue];
      if (inte < 1000 && inte > 0)
         return NO;
      else 
         return YES;
  }

如何在键入期间设置最大值

2 个答案: