显示和隐藏键盘时，UITableView节的页脚问题

Question

I have a UITableView with section headers and footers. In one cell I have a UITextField, which triggers the display of a keyboard.

When the keyboard appears, only sometimes (it somehow depends on the scrolling position of the table) the last section footer is correctly moved upwards, so this footer appears just above the keyboard .

But when I hide the keyboard again, the footer stays in this place, until the table is refreshed by further user interaction. How can I avoid that or at least programmatically enforce the refresh?

tableView.reloadData() does not help.

Note that it only happens on the iPhone, not on iPad. Tested so far with iOS 12.2 only.

Answer 1

override func viewWillAppear(_ animated: Bool) {
    self.registerForKeyboardNotifications()
    super.viewWillAppear(animated)
}

override func viewWillDisappear(_ animated: Bool) {
    self.deregisterFromKeyboardNotifications()
    super.viewWillDisappear(animated)
}



func registerForKeyboardNotifications(){
    //Adding notifies on keyboard appearing
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWasShown(notification:)), name:
        UIResponder.keyboardWillShowNotification, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillBeHidden(notification:)), name: UIResponder.keyboardWillHideNotification, object: nil)
}

func deregisterFromKeyboardNotifications(){
    //Removing notifies on keyboard appearing
    NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillShowNotification, object: nil)
    NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillHideNotification, object: nil)
}


@objc func keyboardWasShown(notification: NSNotification){

    //Need to calculate keyboard exact size due to Apple suggestions
    var info = notification.userInfo!
    let keyboardSize = (info[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue
    //let contentInsets : UIEdgeInsets = UIEdgeInsets(top: 0.0, left: 0.0, bottom: keyboardSize!.size.height, right: 0.0)
}

@objc func keyboardWillBeHidden(notification: NSNotification){
    //Once keyboard disappears, restore original positions
    //var info = notification.userInfo!
    //let keyboardSize = (info[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size
    //let contentInsets : UIEdgeInsets = UIEdgeInsets(top: 0.0, left: 0.0, bottom: -keyboardSize!.height, right: 0.0)

     tableview.transform = CGAffineTransformMakeScale(1, -1);

}