我试图隐藏UISearchController中搜索栏的“取消”按钮,但不幸的是在viewDidLoad()中设置以下内容不起作用: 
  
  
 
override func viewDidLoad() {
    super.viewDidLoad()
    searchResultsTableController = UITableViewController()
    searchResultsTableController.tableView.delegate = self
    searchController = UISearchController(searchResultsController: searchResultsTableController)
    searchController.searchResultsUpdater = self
    searchController.searchBar.sizetoFit()
    searchResultsView.tableHeaderView = searchController.searchBar
    searchController.delegate = self
    searchController.dimsBackgroundDuringPresentation = false
    searchController.searchBar.delegate = self
    searchController.searchBar.searchBarStyle = .Minimal
    searchController.searchBar.showsCancelButton = false
    definesPresentationContext = true
} 
 我也试过在这个委托方法中使用上面的代码:
func didPresentSearchController(searchController: UISearchController) {
    searchController.searchBar.showsCancelButton = false
} 
 这种方法有效但在隐藏之前会短暂显示取消按钮,这并不理想.有什么建议?
解决方法
 我按照建议继承了UISearchBar和UISearchController的子类: 
  
 
        CustomSearchBar.swift
import UIKit
class CustomSearchBar: UISearchBar {
    override func layoutSubviews() {
        super.layoutSubviews()
        setShowsCancelButton(false,animated: false)
    }
} 
 CustomSearchController.swift
import UIKit
class CustomSearchController: UISearchController,UISearchBarDelegate {
    lazy var _searchBar: CustomSearchBar = {
        [uNowned self] in
        let result = CustomSearchBar(frame: CGRectZero)
        result.delegate = self
        return result
    }()
    override var searchBar: UISearchBar {
        get {
            return _searchBar
        }
    }
}