Swift: Is there a method for when someone taps a key on the keyboard?

Question

Is there a method I can use for when any button on the keyboard was tapped on the keyboard that puts input into a text field in Swift? How do I do something (For example display an image in the rightView of the UITextField) when any key that puts input in the UITextField (Excluding, for example, keys like caps lock and the emoji / switch language key) is tapped?

Answer 1

You can do it very easily

Here is the code:

extension ViewController : UITextFieldDelegate {
    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

        let userImageView = UIImageView(image: UIImage(named: "user"))
        userImageView.frame = CGRect(x: 0, y: 0, width: 30, height: 30)
        self.txtField.rightViewMode = .always

        if let textFieldValue = textField.text,
            let textFieldRange = Range(range, in: textFieldValue) {
            let newText = textFieldValue.replacingCharacters(in: textFieldRange, with: string)
            if newText == "" {
                textField.rightView = nil
            } else {
                textField.rightView = userImageView
            }
        }
        return true

    }
}

Output:

If you face any difficulties in this so please let me know.