小编aba*_*arg的帖子

在每个 5G 图中，它们都有直接连接到 UE 的 N1 接口。真的是直连吗？还是仍在通过广播？如果是这样，与 N2 有什么区别？

由于某种原因，当我在搜索字段中输入时，它不会打印出 Xcode 控制台“str”。我在这里缺少什么？我按照他的教程https://www.letsbuildthatapp.com/course_video?id=5232

import UIKit

class SearchViewController: UIViewController {

    let searchController = UISearchController(searchResultsController: nil)

    var sink: Any?

    override func viewDidLoad() {
        super.viewDidLoad()

        setupSearchBarListener()

        navigationItem.searchController = searchController

        navigationController?.navigationBar.prefersLargeTitles = true
        navigationItem.title = "Contact"

        searchController.obscuresBackgroundDuringPresentation = false

        view.backgroundColor = .white
    }

    fileprivate func setupSearchBarListener() {

        let publisher = NotificationCenter.default.publisher(for: UISearchTextField.textDidChangeNotification, object: searchController.searchBar.searchTextField)
        publisher
            .map {
            ($0.object as! UISearchTextField).text
        }
            .debounce(for: .milliseconds(500), scheduler: RunLoop.main)
            .sink { (str) in
                print(str ?? "")
        }

    }
}