add subview over UITableView - ios

Question

First of, I am noob to Swift programming.
I am trying to show a custom view over a UITableView.
I am facing two major issues :
a) The subview does not appear correctly firstly. ref image below :
and after few moments actual view is loaded :
b) After the UITableView is scrolled, the view is not coming over the current top scroll position of UITableView
Following is the code to add subview :
let vaAdPopupViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "AdPopupWithCrossViewController") as! AdPopupWithCrossViewController
vaAdPopupViewController.adID = adID
vaAdPopupViewController.tableView = self.tableView
if let message = parseJSON["adv_text"] as? String{
vaAdPopupViewController.message = message
}
let navigationBarFrame: CGRect = (self.navigationController?.view.frame)!
let frameSize = CGRect(x: navigationBarFrame.minX, y: navigationBarFrame.minY, width: navigationBarFrame.width, height: (navigationBarFrame.height - (self.navigationController?.navigationBar.frame.size.height)!))
vaAdPopupViewController.view.frame = frameSize
self.tableView.addSubview(vaAdPopupViewController.view)
vaAdPopupViewController.view.tag = 1000
self.addChildViewController(vaAdPopupViewController)
vaAdPopupViewController.didMove(toParentViewController: self)
also in AdPopupWithCrossViewController :
override func viewDidLoad() {
self.view.superview?.layoutIfNeeded()
self.view.layoutIfNeeded()
super.viewDidLoad()
}
Please guide me how to resolve this issue.
Thank You.

Answer 1

You probably want to either create a Present Modally Segue or use present() via code.
You've already created your AdPopupWithCrossViewController. Set its background color to be translucent. Then you can present it like this:
let vaAdPopupViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "AdPopupWithCrossViewController") as! ModalOverTableViewController
vaAdPopupViewController.modalPresentationStyle = .overCurrentContext
self.present(vaAdPopupViewController, animated: true, completion: nil)
Then, your little "X" button can remove the ad with:
#IBAction func closeTapped(_ sender: Any) {
self.dismiss(animated: true, completion: nil)
}
You can try out the various options on .modalPresentationStyle and .modalTransitionStyle, as well as setting animated to true or false, to get the appearance / behavior you desire.

Answer 2

As Dan says, you should add your popup as a subview of the view controller's view, not of the table view. A Table view's view hierarchy is private and you should not be trying to mess with it.
Note that you can't do this with a table view controller. This has always bugged me, but it's a fact: A UITableViewController manages a single table view and nothing else. If you want a more complex view hierarchy you need to embed your table view controller in another view controller. I do this with a container view and an embed segue, which is very easy.
If you do that then you can add your new view controller's content to the parent view controller's content view, not to the table view controller's view (or to the table view itself)