问题
When running the App on iOS 13 beta 6, using Xcode 11 beta 5 I'm encountering the strange gap when presenting search results view controller:
Here's a bit of how this is set up:
let searchResultsController = BLSearchResultsController()
let ret = UISearchController(searchResultsController: searchResultsController)
ret.searchResultsUpdater = self
ret.delegate = self
ret.searchBar.delegate = self;
ret.searchBar.autocapitalizationType = .none
ret.searchBar.placeholder = NSLocalizedString("SearchMsg", comment: "")
ret.searchBar.enablesReturnKeyAutomatically = true
if #available(iOS 13.0, *) {
ret.searchBar.showsScopeBar = false
ret.searchBar.backgroundColor = .white
let searchTextField = ret.searchBar.searchTextField
searchTextField.font = UIFont.tuttiRegularFont(16)
searchTextField.accessibilityIdentifier = "Main Search Field"
if let searchImageView = searchTextField.leftView as? UIImageView {
searchImageView.image = UIImage(named: "home-search-icon")
}
}
The results search controller is a normal UITableViewController and is just added to the navigationItem.searchController. There is no fancy presentation code. When building on latest live Xcode and running on the iOS 11/12 device this issue is not present which lead me to believe some underlying iOS 13 change might be causing this glitch.
When debugging the view hierarchy it looks like the result view controller does not reach to the top of the moved search bar.
I've tried fiddling with the modalPresentationModes trying to exclude the possibility that the changes to the presentation could be the cause, had no luck there.
Has anyone encountered this issue and had luck fixing it?
回答1:
Setting
extendedLayoutIncludesOpaqueBars = true
in the UIViewController used to show the search results, fixed the issue for me.
回答2:
We had the same issue and the solution was to set Under Opaque Bars (since we use opaque bars)
We already had Top and Bottom checked, adding the third moved the search results controller to the correct location.
回答3:
For me the problem was that UISearchController didn't update it's frame when search bar moved upwards. I fixed it by setting frame of UISearchController to the frame of it's presenting view controller.
extension UISearchController {
open override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
if let presentingVC = self.presentingViewController {
DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
self.view.frame = presentingVC.view.frame
}
}
}
}
In viewWillAppear animation of search bar did not start so you have to wait for a split second. When animation starts, frame of presenting VC is set to the correct value and then you can update frame of your UISearchController. The solution is a hack but it works fine for me.
回答4:
extendedLayoutIncludesOpaqueBars = true did help to some extent.
Along with this, I had to update
navigationController?.navigationBar.prefersLargeTitles = false
when we start searching and set it back to true when search bar is dismissed.
回答5:
FYI I filed a bug report to apple - according to the WWDC presentation that describes the newly re-written SearchController and some other UI updates, it sounds like the architecture of the SearchController has been re-written from the ground up. I can't believe that this gap we are seeing is expected behavior - I've wasted the better part of two days trying to move past this, and I'm not bothering any further - my app store app is a free app that has a number of users and I wasn't able to devote time to tracking changes/behavior in the API during the beta period, I'm somewhat tired of Apple doing this kind of thing on a yearly basis.
回答6:
- As it was mentioned in above answers, set Extend Edges Under Opaque Bars flag as On for UIViewController which presents search results. For me it was not enough because I use NOT translucent navigation bar.
- So I added the following implementation for methods of UISearchControllerDelegate:
- (void)willPresentSearchController:(UISearchController *)searchController
{
if (@available(iOS 13.0, *))
{
self.navigationController.navigationBar.translucent = YES;
}
}
- (void)willDismissSearchController:(UISearchController *)searchController
{
if (@available(iOS 13.0, *))
{
self.navigationController.navigationBar.translucent = NO;
}
}
回答7:
You must set yours navigationBar.standardAppearance to an UINavigationBarAppearance object that describes a white background.
if #available(iOS 13.0, *) {
let appearance = UINavigationBarAppearance()
appearance.backgroundColor = .white
self.navigationController?.navigationBar.standardAppearance = appearance
}
回答8:
Finally get through the tough. Just to make the first controller contains the UISearchController to have a translucent navigationBar. Work for me perfectly!
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.navigationController?.navigationBar.isTranslucent = true
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillAppear(animated)
self.navigationController?.navigationBar.isTranslucent = false
}
回答9:
I finally solved this by replacing the UISearchController with a simple(r) UISearchBar.
Maybe not the answer you wanted to hear, but the UISsearchController was already a mess on iOS12, the same code on iOS13 works but give horrible UI artifacts. Like disapearing or overlapping searchbar with the header, white space between the searchbar and the first element of the table, or hiding the first list-item under the scope buttons, ... All different issues between iOS12 and 13, but never looking good.
So overall I spent 6 hours trying to fix the searchcontroller, failed, then spent 30 mins migrating to the Searchbar.
I added the UISearchBar simply using Interface Builder in Xcode10.3. For the refactoring, mostly I had to simply replace searchController.searchBar.xx by searchBar.xx . The main effort was to reimplement the UISeachBarDelegates. Just to only show the scopebuttons and cancel button while the user is searching, and removing them afterwards. The code below gives a good overview of what I did:
class MasterViewController: UITableViewController, NSFetchedResultsControllerDelegate {
var fetchedItemsController: NSFetchedResultsController<Item>! = NSFetchedResultsController()
@IBOutlet weak var searchBar: UISearchBar! //hooked up to IB
//GONE IS: let searchController = UISearchController(searchResultsController: nil)
override func viewDidLoad() {
super.viewDidLoad()
initializeFetchedResultsControllerForItems()
//Enable search controller
searchBar.scopeButtonTitles = [NSLocalizedString("Name", comment: ""),
NSLocalizedString("Birthdate", comment: ""),
NSLocalizedString("Employer", comment: "") ]
searchBar.placeholder = NSLocalizedString("Search", comment: "")
searchBar.delegate = self
searchBar.showsScopeBar = false
searchBar.showsCancelButton = false
tableView.contentInsetAdjustmentBehavior = .automatic
self.tableView.tableHeaderView = searchBar //add the searchbar as tableheader view
self.initializeFetchedResultsControllerForItems()
}
// MARK: - Data loading from CoreData
private func initializeFetchedResultsControllerForItems(searchText: String = "", scopeIndex: Int = 0) {
//print("FETCH RESULTS WITH FILTER: \(searchText) en SCOPE: \(scopeIndex)")
//Do whatever searches you need to do to update the FetchedResultsController
//..
self.tableView.reloadData()
}
}
extension MasterViewController: UISearchBarDelegate { //the delegates for the searchbar
func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) {
searchBar.showsScopeBar = true //show the scopebar when users adds text to searchbar
searchBar.showsCancelButton = true //also show the cancel button
searchBar.sizeToFit()
self.tableView.reloadData() //since the scopebar is there, the table needs to move a bit down
}
func searchBarTextDidEndEditing(_ searchBar: UISearchBar) {
}
func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
initializeFetchedResultsControllerForItems(searchText: searchBar.text!, scopeIndex: searchBar.selectedScopeButtonIndex)
}
func searchBar(_ searchBar: UISearchBar, selectedScopeButtonIndexDidChange selectedScope: Int) {
switch (selectedScope) {
case 0: searchBar.placeholder = NSLocalizedString("Seach on name", comment: "")
case 1: searchBar.placeholder = NSLocalizedString("Search on birthdate", comment: "")
case 2: searchBar.placeholder = NSLocalizedString("Search on employer", comment: "")
default: searchBar.placeholder = NSLocalizedString("Search", comment: "")
searchBar.showsScopeBar = true
searchBar.sizeToFit()
}
initializeFetchedResultsControllerForItems(searchText: searchBar.text!, scopeIndex: selectedScope)
}
func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
searchBar.placeholder = NSLocalizedString("Search", comment: "")
searchBar.showsScopeBar = false
searchBar.showsCancelButton = false
searchBar.endEditing(true)
searchBar.text = ""
searchBar.sizeToFit()
initializeFetchedResultsControllerForItems(searchText: searchBar.text!, scopeIndex: searchBar.selectedScopeButtonIndex)
}
}
回答10:
Just bringing my solution. In my case:
edgesForExtendedLayout = .all
on the UIViewController that contains the UISearchController worked.
//MARK: - Properties
var presenter: ExplorePresenting?
var searchController: UISearchController?
var searchUpdater: SearchUpdating?
//MARK: - Lifecycle methods
public override func viewDidLoad() {
super.viewDidLoad()
headerTitle = "explore".localised
tableView.allowsSelection = false
registerCell(cellClass: ExploreTableViewCell.self, with: tableView)
if let searchController = searchController {
searchController.searchBar.delegate = self
searchController.searchResultsUpdater = self
searchController.obscuresBackgroundDuringPresentation = false
searchController.searchBar.placeholder = "explore_search_placeholder".localised
definesPresentationContext = true
navigationItem.hidesSearchBarWhenScrolling = false
navigationItem.searchController = searchController
edgesForExtendedLayout = .all
}
presenter?.viewReady()
}
回答11:
Using .asyncAfter(deadline: .now() + 0.1) will cause a glitch in the UI. To get rid of that, get rid of the deadline! Using DispatchQueue.main.async is enough.
extension UISearchController {
open override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
if let presentingVC = self.presentingViewController {
DispatchQueue.main.async {
self.view.frame = presentingVC.view.frame
}
}
}
}
来源：https://stackoverflow.com/questions/57521967/ios-13-strange-search-controller-gap