在swift中，当键盘还在屏幕上时如何触发按钮动作？

class ViewController: UIViewController, UITextFieldDelegate {
    @IBOutlet weak var textField: UITextField!
    @IBOutlet weak var button: UIButton!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        textField.delegate = self
    }
    
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        button.performClick(nil)
        return true
    }
    
    @IBAction func buttonAction(_ sender: Any) {
        // 执行按钮的动作
    }
}

class ViewController: UIViewController {
    @IBOutlet weak var textField: UITextField!
    @IBOutlet weak var button: UIButton!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        button.addTarget(self, action: #selector(buttonAction), for: .editingDidEndOnExit)
    }
    
    @objc func buttonAction() {
        // 执行按钮的动作
    }
}