顯示和隱藏鍵盤時，UITableView節的頁腳問題

Question

我有一個帶有部分頁眉和頁腳的UITableView 。 在一個單元格中，我有一個UITextField，它觸發鍵盤的顯示。

當出現鍵盤時，僅有時（它在某種程度上取決於表格的滾動位置）最后一個部分的頁腳會正確向上移動，因此此頁腳會出現在keyboard上方。

但是，當我再次隱藏鍵盤時，頁腳將停留在該位置，直到通過進一步的用戶交互刷新表格為止。 如何避免這種情況或至少以編程方式強制執行刷新？

tableView.reloadData()沒有幫助。

請注意，它僅在iPhone上發生，而不在iPad上發生。 到目前為止，僅使用iOS 12.2進行了測試。

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);

}