仅当键盘阻止UITextField / UITextView时才向上移动UIView

NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(_:)), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(_:)), name: UIResponder.keyboardWillHideNotification, object: nil)

@objc func keyboardWillShow(_ notification: Notification) {
    if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        // 根据键盘高度调整界面元素的位置
        let contentInsets = UIEdgeInsets(top: 0, left: 0, bottom: keyboardSize.height, right: 0)
        scrollView.contentInset = contentInsets
        scrollView.scrollIndicatorInsets = contentInsets
        // 滚动到当前活动的文本视图或输入框
        if let activeField = activeField {
            scrollView.scrollRectToVisible(activeField.frame, animated: true)
        }
    }
}

@objc func keyboardWillHide(_ notification: Notification) {
    // 恢复界面元素的位置
    let contentInsets = UIEdgeInsets.zero
    scrollView.contentInset = contentInsets
    scrollView.scrollIndicatorInsets = contentInsets
}

scrollView.contentSize = CGSize(width: view.bounds.width, height: contentHeight)
scrollView.keyboardDismissMode = .onDrag

func textFieldDidBeginEditing(_ textField: UITextField) {
    activeField = textField
}

func textFieldDidEndEditing(_ textField: UITextField) {
    activeField = nil
}

func textViewDidBeginEditing(_ textView: UITextView) {
    activeField = textView
}

func textViewDidEndEditing(_ textView: UITextView) {
    activeField = nil
}