关于搜索栏和Tableview的混淆

我的代码:

import UIKit

struct Human {
    var name = String()
    var surname = String()

}

class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, UISearchBarDelegate {

    @IBOutlet weak var tableView: UITableView!

    @IBOutlet weak var searchBar: UISearchBar!

    var members = [Human]()

    var filteredData = [String]()

    var inSearchMode = false

    var names = ["Oliver","Harold","John","Thea","Felicity"]
    var surnames = ["Queen","Finch","Reese","Queen","Smoak"]

    override func viewDidLoad() {
        super.viewDidLoad()



        for i in 0..<names.count {
            members.append(Human(name: names[i],surname: surnames[i]))
        }



        tableView.delegate = self

        tableView.dataSource = self

        searchBar.delegate = self

        searchBar.returnKeyType = UIReturnKeyType.done
    }

    // MARK: - UITableViewDataSource

    func numberOfSections(in tableView: UITableView) -> Int {

        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

        if inSearchMode {

            return filteredData.count
        }

        return members.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        if let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as? DataCell {

            let text: String!

            if inSearchMode {

                text = filteredData[indexPath.row]

            } else {

                text = members[indexPath.row].name
            }

            cell.congigureCell(text: text)

            return cell

        } else {

            return UITableViewCell()
        }
    }

    func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {

        if searchBar.text == nil || searchBar.text == "" {

            inSearchMode = false

            view.endEditing(true)

            tableView.reloadData()

        } else {

            inSearchMode = true

            filteredData = names.filter { $0.lowercased().contains(searchBar.text!.lowercased()) }

            tableView.reloadData()

        }
    }
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        showAlert(title: "Surname is...", msg: members[indexPath.row].surname)
    }

}

extension UIViewController {

    func showAlert(title: String, msg: String) {
        let alert = UIAlertController(title: title, message: msg, preferredStyle: .alert)
        let action = UIAlertAction(title: "OK", style: .default, handler: nil)
        alert.addAction(action)
        self.present(alert, animated: true, completion: nil)
    }
}

屏幕截图如下:

https://imgur.com/a/aRMNe

最后,我该如何解决这个问题?