Why does my UITableView scroll offset end up behind the UISearchController when returning to its view?

Question

Xcode 11.1, iOS 13.1

I'm having difficulty figuring out why the TableView cells end up behind the search bar.

My setup:

override func viewDidLoad() {
    // Setup Eureka's UITableViewStyle to `Plain`  (like 'Contacts' app)
    // https://github.com/xmartlabs/Eureka/issues/218
    if tableView == nil {
        tableView = UITableView(frame: view.bounds, style: UITableView.Style.plain)
        tableView?.autoresizingMask = UIView.AutoresizingMask.flexibleWidth.union(.flexibleHeight)
        tableView.cellLayoutMarginsFollowReadableWidth = false
    }
    // *now* call super.
    super.viewDidLoad()

    // Add search bar
    searchController.searchResultsUpdater = self
    searchController.obscuresBackgroundDuringPresentation = false
    definesPresentationContext = true

    // Place the search bar in the navigation bar.
    self.navigationItem.searchController = self.searchController
    self.navigationItem.hidesSearchBarWhenScrolling = false
}

please show how you set constraints of tableView. you need to set topAnchor of tableView equal to safeAreaTopAnchor — Enea Dume, Oct 17 '19 at 07:53
@EneaDume This VC is programmatically created, and I actually don't configure any constraints. — Sebastian Dwornik, Oct 17 '19 at 07:57
@EneaDume It's simply inherited, as I'm utilizing the `Eureka` framework that sets up the UITableView and cells for me. https://github.com/xmartlabs/Eureka — Sebastian Dwornik, Oct 17 '19 at 08:12

score 0 · Answer 1 · answered Oct 17 '19 at 08:23

0

Add the following constraints in after tableView = UITableView(frame: view.bounds, style: UITableView.Style.plain)

tableView.translatesAutoresizingMaskIntoConstraints = false
tableView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 0).isActive = true
tableView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: 0).isActive = true
tableView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: 0).isActive = true
tableView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: 0).isActive = true

answered Oct 17 '19 at 08:23

ChrisTheGreat

512
4
21

`*** Terminating app due to uncaught exception 'NSGenericException', reason: 'Unable to activate constraint with anchors and because they have no common ancestor. Does the constraint or its anchors reference items in different view hierarchies? That's illegal.'` – Sebastian Dwornik Oct 17 '19 at 12:09
I switched to using: `tableView.tableHeaderView = searchController.searchBar`, and added your code within `viewWillLayoutSubviews`. Placing the search bar in the navigation bar became too problematic. – Sebastian Dwornik Oct 17 '19 at 14:53
`navigationItem.searchController = searchController` should work. – ChrisTheGreat Oct 18 '19 at 07:19

Sebastian Dwornik · Answer 2 · 2019-11-10T05:07:56.840

After countless more testing on iOS 12 and 13, because I was getting different UX results, I discovered this: https://stackoverflow.com/a/57861125/7599

Which results in: (using Snapkit)

extendedLayoutIncludesOpaqueBars = true

    self.tableView.snp.remakeConstraints { make -> Void in
        make.top.equalToSuperview()
        make.leading.equalTo(self.view.safeAreaLayoutGuide.snp.leading)
        make.trailing.equalTo(self.view.safeAreaLayoutGuide.snp.trailing)
        make.bottom.equalToSuperview()
    }

Why does my UITableView scroll offset end up behind the UISearchController when returning to its view?

2 Answers2