在swift中使用多个numPad键盘textFields时，如何在'doneButtonAction‘方法中获取键盘id？

// 在每个textField上设置tag属性
textField1.tag = 1
textField2.tag = 2
textField3.tag = 3

// 在'doneButtonAction'方法中获取键盘id
@IBAction func doneButtonAction(_ sender: Any) {
    if let textField = UIResponder.currentFirstResponder as? UITextField {
        let keyboardId = textField.tag
        // 使用键盘id进行相应的操作
        print("键盘id：\(keyboardId)")
    }
}

// 扩展UIResponder以获取当前第一响应者
extension UIResponder {
    private weak static var _currentFirstResponder: UIResponder?

    static var currentFirstResponder: UIResponder? {
        _currentFirstResponder = nil
        UIApplication.shared.sendAction(#selector(findFirstResponder(_:)), to: nil, from: nil, for: nil)
        return _currentFirstResponder
    }

    @objc private func findFirstResponder(_ sender: Any) {
        UIResponder._currentFirstResponder = self
    }
}