当 UISearchController 处于活动状态时呈现 UIAlertController

Question

我有一个 UITableView，它的导航栏中有一个 UISearchController。 table 视图内容随着用户在搜索栏中键入内容而更新。当一行被 selected 时，另一个 table 视图控制器被推送到导航堆栈。在那个新的 table 视图控制器上，有一个显示操作 sheet 的条形按钮项。问题是，当我在使用搜索控制器后 select 一行然后尝试在新的 table 视图控制器上打开操作 sheet 时，我得到

Attempt to present <UIAlertController: 0x103971800>  on <KYFB_Black_Book.MembersTableViewController: 0x103854c00> which is already presenting (null)

如果我从第一个控制器 select 一行而不搜索，然后在第二个控制器上打开操作 sheet，一切正常。

在第一个控制器的 viewDidLoad() 中：

searchController = UISearchController(searchResultsController: nil)
        searchController.searchResultsUpdater = self
        searchController.searchBar.tintColor = .white
        searchController.dimsBackgroundDuringPresentation = false
        searchController.hidesNavigationBarDuringPresentation = false
        let searchField = searchController.searchBar.value(forKey: "searchField") as? UITextField
        searchField?.textColor = .white

        if #available(iOS 11.0, *) {
            navigationItem.searchController = searchController
            navigationItem.hidesSearchBarWhenScrolling = false
        } else {
            searchController.searchBar.frame = CGRect(x: 0, y: 0, width: 200.0, height: 44.0)
            searchField?.textColor = .black
            searchController.searchBar.tintColor = .black
            navigationItem.titleView = searchController.searchBar
        }

正在根据搜索文本更新结果：

@available(iOS 8.0, *)
    func updateSearchResults(for searchController: UISearchController) {
        filteredCountyNames.removeAll(keepingCapacity: false)
        let searchPredicate = NSPredicate(format: "SELF CONTAINS[c] %@", searchController.searchBar.text!)
        let array = (countyNames as NSArray).filtered(using: searchPredicate)
        filteredCountyNames = array as! [String]
        tableView.reloadData()
    }

在第二个控制器中，显示警报控制器：

@objc func actionTapped() {
        let emailAlert = UIAlertController(title: "Contact All Committee Members", message: "", preferredStyle: .actionSheet)
        let cancelAction = UIAlertAction(title: "Cancel", style: .destructive, handler: { (action) in
            print("Cancel")
            })
        let emailAction = UIAlertAction(title: "Email", style: .default, handler: { (action) in
            self.emailAll()
            })
        let messageAction = UIAlertAction(title: "Text Message", style: .default, handler: { (action) in
            self.textAll()
            })

        emailAlert.view.tintColor = UIColor(red: 28.0 / 255.0, green: 75.0 / 255.0, blue: 136.0 / 255.0, alpha: 1)
        emailAlert.addAction(emailAction)
        emailAlert.addAction(messageAction)
        emailAlert.addAction(cancelAction)
        present(emailAlert, animated: true, completion: nil)
    }

Answer 1

你能试试看是否有效吗？只需替换代码中显示操作的最后一行 sheet.

if let presentedVC = presentedViewController {
    presentedVC.present(emailAlert, animated: true, completion: nil)
} else {
    present(emailAlert, animated: true, completion: nil)
}

Answer 2

我在使用 UISearchController 并尝试呈现 UIAlertController 时遇到了同样的错误。试试这个：

override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        // To avoid the problem
        search.dismiss(animated: false, completion: nil)
    }

当 UISearchController 处于活动状态时呈现 UIAlertController

Presenting UIAlertController when UISearchController is Active

ios

swift

uialertcontroller

uisearchcontroller