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使搜索栏通知viewController用户将要搜索

protocols swift ios

Swifty · 技术社区 · 8 年前

我正在我的应用程序中实现搜索功能。该应用程序由一个视图控制器和一个处理搜索逻辑的自定义类组成。此自定义类称为 SearchController

UISearchBarDelegate 方法 searchBarShouldBeginEditing ).

搜索栏应开始编辑 里面但是我试着从内部调用这个方法 viewController 因为我希望在发生此事件时视图中的某些内容发生更改(因此应该由viewController而不是searchController来处理)。

班级:

class SearchController: NSObject, UISearchBarDelegate {

    let searchBar = UISearchBar()
    var searchButton = UIBarButtonItem? = nil

    /* Other irrelevant class properties */

    func setup() {
        searchBar.delegate = self
        /* other setup */
    }
}

ViewController 班级:

class ViewController: UIViewController {

    private let searchController = SearchController()  

    override func viewDidLoad() {
        super.viewDidLoad()

        searchController.delegate = self
        searchController.setup()
    }

    /* setup a tableview to display results... this part of the implementation works fine */
}

视图控制器

我试着实施但我已经做了实施 UISearchBarDelegate公司 为什么我不能访问里面的委托方法呢 视图控制器 ?

我希望我自己说清楚,我可以进一步澄清这个职位,如果必要的话。我一直在绞尽脑汁想自己解决这个问题。

2 回复 | 直到 8 年前

Sam Peters 8 年前

好的,a searchBar

一种方法是:

protocol SearchControllerDelegate: class{
    func searchBarDidBeginEditing()
}

class SearchController: NSObject, UISearchBarDelegate {

    weak var delegate: SearchControllerDelegate?

    private let searchBar = UISearchBar()

    func setup() {
        searchBar.delegate = self
    }

    func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) {
        delegate?.searchBarDidBeginEditing()
    }

}

class ViewController: UIViewController, SearchControllerDelegate{

    var searchController = SearchController()
    func setUP(){
        self.searchController.delegate = self
    }

    func searchBarDidBeginEditing() {
        /// perform some action here
    }

}

thy.nguyen 8 年前

你可以用 UISearchController UISearchResultsUpdating

视图控制器

 class ViewController: UIViewController, UISearchResultsUpdating {
    private let searchController = UISearchController(searchResultsController:  nil) 

    override func viewDidLoad() {
        super.viewDidLoad()

        searchController.searchResultsUpdater = self
        searchController.delegate = self

        ....
    }

    // Called when the search bar's text or scope has changed or when the search bar becomes first responder.
    func updateSearchResults(for searchController: UISearchController) {
        //Do something...
    }
}

或者,如果您真的想自己实现搜索栏逻辑,可以使用闭包:

搜索控制器

class SearchController: NSObject, UISearchBarDelegate {

    let searchBar = UISearchBar()
    var searchButton = UIBarButtonItem? = nil
    var didBeginSearching: (() -> ())?

    /* Other irrelevant class properties */

    func setup() {
        searchBar.delegate = self
        /* other setup */
    }

    func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) {
        didBeginSearching?()
    }
}

视图控制器 班级:

class ViewController: UIViewController {

    private let searchController = SearchController() 

    override func viewDidLoad() {
        super.viewDidLoad()

        searchController.setup()
        searchController.didBeginSearching = { [weak self] in
            //Do something...
        }
    }
}