UITextField : restrict the maximum allowed value (number) during inputting

Question

I have a UITextField, I\'d like to restrict the maximum allowed input value in the field to be 1000. That\'s when user is inputting number inside, once the inpu

Answer 1

I created a class with the help method that can be call from any place in your project.

Swift code:

class TextFieldUtil: NSObject {

    //Here I am using integer as max value, but can change as you need
    class func validateMaxValue(textField: UITextField, maxValue: Int, range: NSRange, replacementString string: String) -> Bool {

        let newString = (textField.text! as NSString).stringByReplacingCharactersInRange(range, withString: string)

        //if delete all characteres from textfield
        if(newString.isEmpty) {
            return true
        }

        //check if the string is a valid number
        let numberValue = Int(newString)

        if(numberValue == nil) {
            return false
        }

        return numberValue <= maxValue
    }
}

Then you can use in your uiviewcontroller, in textfield delegate method with any textfield validations

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

    if(textField == self.ageTextField) {
        return TextFieldUtil.validateMaxValue(textField, maxValue: 100, range: range, replacementString: string)
    }
    else if(textField == self.anyOtherTextField) {
        return TextFieldUtils.validateMaxValue(textField, maxValue: 1200, range: range, replacementString: string)
    }
    return true
}