为UITextField或UITextView显示键盘时调整界面

为了调整界面以适应 UITextField 或 UITextView 的键盘显示，您可以使用以下方法：

使用 UIKeyboardWillShowNotification 和 UIKeyboardWillHideNotification 通知来监听键盘的显示和隐藏。
在通知中，获取键盘的高度和动画时长，并根据这些信息调整界面。
使用 UIScrollView 来包含您的输入控件，并在键盘显示时调整 contentInset 属性，以便在输入时不遮挡输入控件。

以下是一个简单的示例代码：

override func viewDidLoad() {
    super.viewDidLoad()
    
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: UIResponder.keyboardWillShowNotification, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: UIResponder.keyboardWillHideNotification, object: nil)
}

@objc func keyboardWillShow(notification: NSNotification) {
    guard let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue else { return }
    guard let duration = notification.userInfo?[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double else { return }
    guard let curve = notification.userInfo?[UIResponder.keyboardAnimationCurveUserInfoKey] as? UInt else { return }
    
    let insets = UIEdgeInsets(top: 0, left: 0, bottom: keyboardSize.height, right: 0)
    
    UIView.animate(withDuration: duration, delay: 0, options: UIView.AnimationOptions(rawValue: curve), animations: {
        self.scrollView.contentInset = insets
        self.scrollView.scrollIndicatorInsets = insets
    }, completion: nil)
}

@objc func keyboardWillHide(notification: NSNotification) {
    guard let duration = notification.userInfo?[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double else { return }
    guard let curve = notification.userInfo?[UIResponder.keyboardAnimationCurveUserInfoKey] as? UInt else { return }
    
    UIView.animate(withDuration: duration, delay: 0, options: UIView.AnimationOptions(rawValue: curve), animations: {
        self.scrollView.contentInset = .zero
        self.scrollView.scrollIndicatorInsets = .zero
    }, completion: nil)
}

这段代码将监听键盘的显示和隐藏，并在键盘显示时调整 UIScrollView 的 contentInset 属性，以便在输入时不遮挡输入控件。当键盘隐藏时，将恢复 contentInset 的值。