加载 UISearchController 时自动显示键盘

Question

我在 table 视图控制器中创建了一个 UISearchController。我使用来自另一个视图控制器的推送 segue 转至此 table 视图控制器。我希望键盘在按下 table 视图控制器后立即在搜索栏中显示光标。

我使用

在 viewDidLoad 方法中激活了搜索控制器

self.mySearchController.active = true

它确实使搜索控制器处于活动状态，但这不会调出键盘，也不会将光标放在搜索栏中。我也试过了

self.mySearchController.searchBar.becomeFirstResponder()

这一行好像没有任何作用。

如何调出键盘 automatically/programmatically？下面是我的代码的更详细版本

class PickAddressViewController: UITableViewController, UISearchResultsUpdating {

var searchText = ""

var mySearchController = UISearchController()

override func viewDidLoad() {
    super.viewDidLoad()

    self.mySearchController = ({
        let controller = UISearchController(searchResultsController: nil)
        controller.searchResultsUpdater = self
        controller.dimsBackgroundDuringPresentation = false
        controller.searchBar.sizeToFit()
        controller.searchBar.text = self.searchText

        self.tableView.tableHeaderView = controller.searchBar

        return controller
    })()

    self.mySearchController.active = true
    self.mySearchController.searchBar.becomeFirstResponder()
}

Answer 1

BecomeFirstResponder 是可行的方法，但您不应在 viewDidLoad 中执行此操作。查看以下讨论以了解详细信息 -

Answer 2

我也尝试了 Nikita Leonov 提到的 link 中列出的建议。我需要添加 make the class a UISearchControllerDelegate & UISearchBarDelegate 然后它起作用了。我没有你

class PickAddressViewController: UITableViewController, UISearchControllerDelegate, UISearchBarDelegate, UISearchResultsUpdating {

    override func viewDidLoad() {
        super.viewDidLoad()

        self.mySearchController = ({
            controller.searchBar.delegate = self
        })()

        self.mySearchController.active = true
        self.mySearchController.delegate = self
    }

    func didPresentSearchController(searchController: UISearchController) {
        self.mySearchController.searchBar.becomeFirstResponder()
    }
    …
}

Answer 3

除了按照其他用户的建议进行操作外，我还进行了以下操作，并且奏效了：

searchController.definesPresentationContext = true

Answer 4

override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(true)
    self.navigationItem.titleView = searchController!.searchBar
    dispatch_async(dispatch_get_main_queue(), {
        self.searchController?.active = true
        self.searchController!.searchBar.becomeFirstResponder()
    })
}

和这段代码

func presentSearchController(searchController: UISearchController) {
    searchController.searchBar.becomeFirstResponder()
}

确保你给 searchController?.delegate = self 在 viewDidLoad() 中。在 iOS 9.* 设备

上测试

Answer 5

Swift 3 在我的案例中的解决方案：

override func viewDidLoad() {
    super.viewDidLoad()
    navigationItem.titleView = mySearchController.searchBar
    mySearchController.searchResultsUpdater = self
    mySearchController.delegate = self

}

override func viewDidAppear(_ animated: Bool) {
    DispatchQueue.main.async {
        self.mySearchController.isActive = true
    }
}

func presentSearchController(_ searchController: UISearchController) {
    mySearchController.searchBar.becomeFirstResponder()
}

Answer 6

Swift 5

在viewDidLoad中：

searchViewController.delegate = self

在viewDidAppear中：

searchViewController.isActive = true

这将激活 SearchController

定义委托方法：

extension MyViewController: UISearchControllerDelegate {
    func didPresentSearchController(_ searchController: UISearchController) {
        DispatchQueue.main.async {
            searchController.searchBar.becomeFirstResponder()
        }
    }
}

加载 UISearchController 时自动显示键盘

Show keyboard automatically when UISearchController is loaded

ios

swift

uisearchcontroller

Swift 5