Set the maximum character length of a UITextField

Question

How can I set the maximum amount of characters in a UITextField on the iPhone SDK when I load up a UIView?

Answer 1

Use below extension to set the maximum character length of a UITextField and UITextView.

Swift 4.0

    private var kAssociationKeyMaxLength: Int = 0
    private var kAssociationKeyMaxLengthTextView: Int = 0
    extension UITextField {


        @IBInspectable var maxLength: Int {
            get {
                if let length = objc_getAssociatedObject(self, &kAssociationKeyMaxLength) as? Int {
                    return length
                } else {
                    return Int.max
                }
            }
            set {
                objc_setAssociatedObject(self, &kAssociationKeyMaxLength, newValue, .OBJC_ASSOCIATION_RETAIN)
                addTarget(self, action: #selector(checkMaxLength), for: .editingChanged)
            }
        }

        @objc func checkMaxLength(textField: UITextField) {
            guard let prospectiveText = self.text,
                prospectiveText.count > maxLength
                else {
                    return
            }

            let selection = selectedTextRange

            let indexEndOfText = prospectiveText.index(prospectiveText.startIndex, offsetBy: maxLength)
            let substring = prospectiveText[..

UITextView

extension UITextView:UITextViewDelegate {


        @IBInspectable var maxLength: Int {
            get {
                if let length = objc_getAssociatedObject(self, &kAssociationKeyMaxLengthTextView) as? Int {
                    return length
                } else {
                    return Int.max
                }
            }
            set {
                self.delegate = self

                objc_setAssociatedObject(self, &kAssociationKeyMaxLengthTextView, newValue, .OBJC_ASSOCIATION_RETAIN)
            }
        }

        public func textViewDidChange(_ textView: UITextView) {
            checkMaxLength(textField: self)
        }
        @objc func checkMaxLength(textField: UITextView) {
            guard let prospectiveText = self.text,
                prospectiveText.count > maxLength
                else {
                    return
            }

            let selection = selectedTextRange

            let indexEndOfText = prospectiveText.index(prospectiveText.startIndex, offsetBy: maxLength)
            let substring = prospectiveText[..

You can set limit below.