键盘多次出现时，Scrollview不会向上移动

Question

我做了30个文本框，并var scrollview: UIScrollView在viewDidLoad()和我试图拉升整体向上滚动视图时，键盘盖文本框。Delegate的文本字段和scrollview已经设置。此代码（下面向下）有效，并且第一次出现键盘时scrollview会向上移动，但是问题是，当第二次或更多次打开键盘时，scrollview不会向上移动，我一直无法解决问题几个小时。谁能在我的代码中检测到一些错误并给出正确答案？我期待任何帮助！

我写的代码是这样的：

var activeField: UITextField?

func registerForKeyboardNotifications(){
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWasShown(notificaiton:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillBeHidden(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}

func deregisterForKeyboardNotifications(){
    NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    NotificationCenter.default.removeObserver(self, name:NSNotification.Name.UIKeyboardWillHide, object: nil)
}

@objc func keyboardWasShown(notificaiton: NSNotification){
    var info = notificaiton.userInfo!
    let keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size
    let contentInsets: UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize!.height, 0.0)
    var aRect: CGRect = view.frame
    aRect.size.height -= keyboardSize!.height

    if let activeField = activeField{
        if !aRect.contains(activeField.frame.origin) == true{
            scrollview.contentInset = contentInsets
        }
    }
}

@objc func keyboardWillBeHidden(notification: NSNotification){
    view.endEditing(true)
}

func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool{
    activeField = textField
    registerForKeyboardNotifications()
    return true
}

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

Answer 1

朋友请尝试这段代码。希望它也对您有用。我正在使用它，并且效果很好。

 override func viewDidLoad(){
    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardDidShow), name: NSNotification.Name.UIKeyboardDidShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardDidHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}

//MARK: Methods to manage keybaord
@objc func keyboardDidShow(notification: NSNotification) {
    var info = notification.userInfo
    let keyBoardSize = info![UIKeyboardFrameEndUserInfoKey] as! CGRect
    scrollView.contentInset = UIEdgeInsetsMake(0.0, 0.0, keyBoardSize.height, 0.0)
    scrollView.scrollIndicatorInsets = UIEdgeInsetsMake(0.0, 0.0, keyBoardSize.height, 0.0)
}

@objc func keyboardDidHide(notification: NSNotification) {

    scrollView.contentInset = UIEdgeInsets.zero
    scrollView.scrollIndicatorInsets = UIEdgeInsets.zero
}

我已经为Swift 4.0编写了此代码。