textField.characther range
ViewController: UIViewController, UITextFieldDelegate { //create textfield view constructor let myTextField : UITextField = { let textField = UITextField() textField.backgroundColor = .white textField.translatesAutoresizingMaskIntoConstraints = false return textField }() override func viewDidLoad() { super.viewDidLoad() view.backgroundColor = UIColor(red: 243/255, green: 243/255, blue: 243/255, alpha: 1) myTextField.delegate = self// must write this line setUpViews()// call func for constraint } //func for text limit func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool { let curruntCharachterCount = textField.text?.count ?? 0 if range.length + range.location > curruntCharachterCount{ return false } let newLength = curruntCharachterCount + string.count - range.length return newLength <= 1 // set max limit of numbers } func setUpViews() { //constraint setup view.addSubview(enterPinTextField) //textField constraint enterPinTextField.topAnchor.constraint(equalTo: view.topAnchor, constant: 30).isActive = true enterPinTextField.centerXAnchor.constraint(equalTo: mainScreenView.centerXAnchor).isActive = true enterPinTextField.widthAnchor.constraint(equalToConstant: 150).isActive = true enterPinTextField.heightAnchor.constraint(equalToConstant: 50).isActive = true } }
