ios - 出现键盘时尝试移动 View - 一些错误

Question

我试图将我的整个 View 向上移动，以便能够看到用户在文本字段中输入的内容。但是，它第一次完美地工作，正如我所希望的那样。但是，当单击键盘上的返回键(将其关闭)，然后单击文本字段时，我将键盘稍微放在文本字段上方，并且没有得到与第一次相同的结果。这是为什么？

这是我的代码:

@IBOutlet weak var commentTextField: UITextField!

override func viewDidLoad() {
    super.viewDidLoad()

    commentTextField.delegate = self

    //Keyboard listeners
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: NSNotification.Name.UIKeyboardDidShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardDidHide, object: nil)
}

@objc func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        if self.view.frame.origin.y == 0 {
            self.view.frame.origin.y -= keyboardSize.height
        }
    }
}

@objc func keyboardWillHide(notification: NSNotification) {
    if self.view.frame.origin.y != 0 {
        self.view.frame.origin.y = 0
    }
}

func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    commentTextField.resignFirstResponder()
    return true
}    

Answer 1

替换

UIKeyboardFrameBeginUserInfoKey

与

UIKeyboardFrameEndUserInfoKey