以编程方式将搜索栏快速添加到表格视图中

我有一个文本字段，它代表一个表视图作为其输入视图。我想在这个表格视图中添加两件事。

1）添加搜索栏。
2）在表格视图顶部添加取消按钮。

class enterYourDealVC: UIViewController, UITableViewDataSource, UITableViewDelegate, UISearchBarDelegate, UISearchDisplayDelegate, UISearchResultsUpdating {
var tableView: UITableView  =   UITableView()
let searchController = UISearchController(searchResultsController: nil)

var dealAirports = [
    airPorts(name: "Airport1", shortcut: "AP1")!),
    airPorts(name: "Airport2", shortcut: "AP2")!)
]
var filteredAirports = [airPorts]()


//view did load
    tableView = UITableView(frame: UIScreen.mainScreen().bounds, style: UITableViewStyle.Plain)
    tableView.delegate      =   self
    tableView.dataSource    =   self
    tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "cell")

    searchController.searchResultsUpdater = self
    searchController.dimsBackgroundDuringPresentation = false
    definesPresentationContext = true
    tableView.tableHeaderView = searchController.searchBar
    toTextField.inputView = self.tableView

//here is my search function
func filterContentForSearchText(searchText: String, scope: String = "All") {
    filteredAirports = dealAirports.filter { ap in
        return ap.name.lowercaseString.containsString(searchText.lowercaseString)
    }

    tableView.reloadData()
}
}

问题出在这段代码上，它不进行搜索。此外，当我单击搜索栏时，它会关闭表格视图并将我返回到视图控制器。我怎样才能解决这个问题？

如何向该表视图添加取消按钮？

这将添加一个搜索栏

lazy var searchBar:UISearchBar = UISearchBar()

override func viewDidLoad()
{
     searchBar.searchBarStyle = UISearchBar.Style.default
    searchBar.placeholder = " Search..."
    searchBar.sizeToFit()
    searchBar.isTranslucent = false
    searchBar.backgroundImage = UIImage()
    searchBar.delegate = self
    navigationItem.titleView = searchBar

}

func searchBar(_ searchBar: UISearchBar, textDidChange textSearched: String)
{
    ...your code...
}