UISearchController 关闭时屏幕滞后

Question

预期：

点击 UIButton 时，显示 viewcontroller 模态，其中包含搜索控制器和带结果的表格视图。

点击列表中的项目时，将搜索栏的文本更改为所点击的内容，然后关闭 viewcontroller 回到原来的状态，现在 UIButton 设置为该文本。

实际：

UIButton 调用 segue 到 searchViewController。 searchViewController 显示并正确配置 searchController 和 tableView。点击单元格调用退出转场，展开到原始屏幕并正确更新 UIButton 和搜索栏中的文本...

但是，展开后出现异常的白屏，这让我抓狂。

已尝试缓解措施：

退出 searchController 然后调用 segue 以编程方式
在 didSelectRowAt
通过以下方式将解雇放在主线程上：DispatchQueue.main.async { }
调用 self.presentingViewController?.dismiss（动画：真）

Video Demo of flashing

代码：

SearchDetailsViewController - Viewcontroller 放松到

import UIKit

class SearchDetailsViewController: UIViewController {

  @IBOutlet weak var destinationButton: UIButton!
  override func viewDidLoad() {
    super.viewDidLoad()
  }

  override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    if searchDestination != "" {
        destinationButton.setTitle(searchDestination, for: UIControlState.normal)
        destinationButton.setTitleColor(UIColor.black, for: UIControlState.normal)
    } else {
        destinationButton.setTitle("Search Nearby", for: UIControlState.normal)
    }
  }

  @IBAction func unwindToSearchDetailsViewController(segue: UIStoryboardSegue){
  }
}

SearchViewController - 问题 child。我目前将 tableview 单元格作为情节提要中的退出 segue。

    class SearchViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, UISearchResultsUpdating, UISearchBarDelegate, UISearchControllerDelegate {


    @IBOutlet weak var searchResultsTableView: UITableView!

    var destinationsObj:[String:[String]] = [:]
    var destinations:[String] = []
    var defaultDestinations:[String] = ["Search Nearby"]
    var filteredDestinations:[String] = ["Search Nearby"]
    var shouldShowSearchResults = false

    var searchActive:Bool = false
    var searchController: UISearchController!

    override func viewDidLoad() {
        super.viewDidLoad()

        defaultDestinations = recentSearches
        configureTableView()
        configureSearchController()

    }

    override func viewDidAppear(_ animated: Bool) {
        // Show search bar keyboard
        searchController.isActive = true
        DispatchQueue.main.async {
            self.searchController.searchBar.becomeFirstResponder()
        }

    }


    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    // MARK: Configure Functions
    func configureSearchController() {
        searchController = UISearchController(searchResultsController: nil) //nil lets the view controller also be the search results
        searchController.searchResultsUpdater = self
        searchController.dimsBackgroundDuringPresentation = false

        searchController.searchBar.placeholder = "Where to?"
        searchController.searchBar.delegate = self

        searchController.searchBar.sizeToFit()
        searchResultsTableView.tableHeaderView = searchController.searchBar
        searchController.delegate = self

    }

    func configureTableView() {
        searchResultsTableView.delegate = self
        searchResultsTableView.dataSource = self

        //searchResultsTableView.isMultipleTouchEnabled = false
    }

    // MARK: TableView Delegate Functions
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

        if shouldShowSearchResults {
            return filteredDestinations.count
        } else {
            return defaultDestinations.count
        }
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "idCell", for: indexPath)

        if shouldShowSearchResults {
            cell.textLabel?.text = filteredDestinations[indexPath.row]
        } else {

            cell.textLabel?.text = defaultDestinations[indexPath.row]
        }

        return cell
    }

    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        return 40.0
    }

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {


        if let value = tableView.cellForRow(at: indexPath)?.textLabel?.text {
            self.searchController.searchBar.text = value
            searchDestination = value
            if !recentSearches.contains(value) {
                recentSearches.append(value)
            }

        }
        //self.searchController.resignFirstResponder()
//        tableView.deselectRow(at: indexPath, animated: false)
//        DispatchQueue.main.async {
//            self.dismiss(animated: true, completion: nil)
//        }

       // self.performSegue(withIdentifier: "cancelSearchSegue", sender: self)
    }

    // MARK: UISearchBar Delegate Functions
    func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
        searchBar.resignFirstResponder()
        //self.dismiss(animated: true, completion: nil)
        self.performSegue(withIdentifier: "cancelSearchSegue", sender: self)
    }

    func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {

        if let value = searchBar.text {
            searchDestination = value
            if !recentSearches.contains(value) {
                recentSearches.append(value)
            }
        }


        //self.dismiss(animated: true, completion: nil)
        self.performSegue(withIdentifier: "cancelSearchSegue", sender: self)
    }

    func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) {

    }


    func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
        shouldShowSearchResults = true
        if searchText.characters.count > 1 {
            return
        } else {
            if let firstLetter = searchText.characters.first{
                print("Typed \(firstLetter)")
                getPredictionData(firstLetter:firstLetter.description)
            }
        }
    }

    func dismissCurrentView() {
       // self.presentingViewController?.dismiss(animated: true, completion: nil)
        self.performSegue(withIdentifier: "cancelSearchSegue", sender: self)
    }

Screenshot of my storyboard

Answer 1

好吧，我想我 post 答案是为了防止其他人遇到这种情况。

在 ViewDidAppear 中，我将 searchController 设置为活动 searchController.isActive = 真

在我解散之前，我需要将其设置为不活动！

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
  if let value = tableView.cellForRow(at: indexPath)?.textLabel?.text {
    self.searchController.searchBar.text = value
    searchDestination = value
    if !recentSearches.contains(value) {
        recentSearches.append(value)
    }
  }
 self.searchController.isActive = false
 self.performSegue(withIdentifier: "cancelSearchSegue", sender: self)
}

Answer 2

不要执行 segue，尝试直接关闭视图控制器并在关闭之前将呈现视图控制器的属性设置为搜索结果

UISearchController 关闭时屏幕滞后

Screen lags when UISearchController dismissed

uitableview

uiviewcontroller

ios

uisearchcontroller

swift3