swift - MapKit SearchResultsUpdating 未调用

Question

有人可以审查我的代码吗？我正在尝试使用 MapKit 获取本地搜索结果。我使用了这个教程:https://www.thorntech.com/2016/01/how-to-search-for-location-using-apples-mapkit/

与教程和我正在做的事情的区别在于我不想显示 map View 。我只想单击按钮，然后会弹出一个 searchController，让我可以搜索位置。我遇到的问题是 SearchResultsUpdating 没有被调用。抱歉代码很长，这是我第一次使用 MapKit 本地搜索，我不知道我错过了什么。

*编辑已修复。附上修改后的代码。

import UIKit
import MapKit
import CoreLocation

class LocationSearchTable: UITableViewController {
let cellId = "cellId"
var searchController = UISearchController(searchResultsController: nil)

var matchingItems: [MKMapItem] = []
let mapView = MKMapView()
let locationManager = CLLocationManager()

override func viewDidLoad() {
    super.viewDidLoad()

    setupLocationManager()
    setupSearchBar()
    setupMapView()

    tableView.delegate = self
    tableView.dataSource = self
    tableView.register(UITableViewCell.self, forCellReuseIdentifier: cellId)
    navigationController?.isNavigationBarHidden = false
    navigationItem.hidesSearchBarWhenScrolling = false
}

fileprivate func setupLocationManager() {
    locationManager.delegate = self
    locationManager.desiredAccuracy = kCLLocationAccuracyBest
    locationManager.requestWhenInUseAuthorization()
    locationManager.requestLocation()
}

fileprivate func setupSearchBar() {
    let searchBar = searchController.searchBar
    searchBar.placeholder = "Enter Location"
    navigationItem.searchController = searchController
    searchController.searchResultsUpdater = self
    definesPresentationContext = true
}

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath)
    let selectedItem = matchingItems[indexPath.row].placemark
    cell.textLabel?.text = selectedItem.name
    cell.detailTextLabel?.text = ""
    return cell
}

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return matchingItems.count
}
}

extension LocationSearchTable: CLLocationManagerDelegate {
func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
    if status == .authorizedWhenInUse {
        locationManager.requestLocation()
    }
}

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    if let location = locations.first {
        let span = MKCoordinateSpan(latitudeDelta: 0.05, longitudeDelta: 0.05)
        let region = MKCoordinateRegion(center: location.coordinate, span: span)
        mapView.setRegion(region, animated: true)
        print("location: \(location)")
    }
}

func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
    print(error)
}
}

extension LocationSearchTable: UISearchResultsUpdating {
func updateSearchResults(for searchController: UISearchController) {
    if let searchText = searchController.searchBar.text {
        let request = MKLocalSearch.Request()
        request.naturalLanguageQuery = searchText
        request.region = mapView.region

        let search = MKLocalSearch(request: request)
        search.start { (response, _) in
            guard let response = response else { return }
            self.matchingItems = response.mapItems
            self.tableView.reloadData()
        }
    }
}
}    

Answer 1

我们首先尝试让 searchController 工作。

按照此设置 searchController

1. 声明搜索 Controller ，你已经得到了这个。让 searchController = UISearchController(searchResultsController: nil)
2. 在viewDidLoad()中

navigationItem.searchController = searchController
searchController.searchResultsUpdater = self
definesPresentationContext = true

设置搜索 Controller 文本更新，确保您的 Controller 符合 UISearchResultsUpdating 协议(protocol)

extension LocationSearchTable: UISearchResultsUpdating {
    func updateSearchResults(for searchController: UISearchController) {
        if let searchText = searchController.searchBar.text {
            print(searchText)
        }
    }
}

<小时/>

当我们使用UISearchController时，我们不需要设置searchBar。

下面的评论让我知道搜索文本是否可以打印出来。然后我们就可以继续了。