Question

我正在关注本教程：https://www.raywenderlich.com/4363809-uisearchcontroller-tutorial-getting-started

这是相关的代码。唯一的问题是搜索栏不可见。在本教程中，他创建了一个UISearchController，奇迹般地出现了搜索栏（尽管它不在情节提要中的任何地方，所以我无法解释它对他的工作原理）：

import UIKit
import RealmSwift

class PlacesViewController: UIViewController{
    @IBOutlet weak var tableView: UITableView!
    var places11:Results<Place11>?
    let searchController = UISearchController(searchResultsController: nil)
    
    var filteredPlaces: [Place11] = []
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        places11 = PlaceService.getPlaces11()
        tableView.delegate = self
        tableView.dataSource = self
        searchController.searchResultsUpdater = self
        searchController.obscuresBackgroundDuringPresentation = false
        searchController.searchBar.placeholder = "Search Permits"
        navigationItem.searchController = searchController
        definesPresentationContext = true
}

    func filterContentForSearchText(_ searchText: String) {
        let array = places11?.toArray(type: Place11.self)
        filteredPlaces = array!.filter { (place: Place11) -> Bool in
            let bool2 = (place.description.lowercased().contains(searchText.lowercased()) )
            return bool2
        }
        
        tableView.reloadData()
    } 

    
    var isSearchBarEmpty: Bool {
        return searchController.searchBar.text?.isEmpty ?? true
    }
    
    var isFiltering: Bool {
        return searchController.isActive && !isSearchBarEmpty
    }
    

}



extension PlacesViewController: UISearchResultsUpdating {
    func updateSearchResults(for searchController: UISearchController) {
        let searchBar = searchController.searchBar
        let text = searchBar.text!
        filterContentForSearchText(text)
        
    }
}

Answer 1

使搜索栏出现在导航栏中的是此行：

navigationItem.searchController = searchController

问题是您的视图控制器不属于导航界面。没有导航控制器，也没有导航栏，因此搜索栏无处可寻。

XCode 11.4 UISearchBar不可见

1 个答案: