ios – 将UISearchController与UINavigationController一起使用

我遇到的问题与 here相同,没有任何答案. (将searchController.active设置为false会清除搜索文本,这是我不想要的.)我想使用UISearchController,以便用户可以搜索我的UITableView中的项目列表.我在Interface Builder中连接了一个show segue,它在选择表视图的单元格时触发.
 问题是,如果用户搜索某些内容然后单击该表格的单元格,当它转移到新视图时,搜索栏就会位于该位置.理想情况下,我希望在用户搜索时导航栏被搜索栏“替换”,然后在用户点击单元格时返回导航栏,然后在用户单击时返回搜索栏“返回键. (这是现在已弃用的UISearchdisplayController的工作方式.)如何实现这一目标？这是我的表视图的控制器.

class ItemSearchViewController: UITableViewController,UISearchResultsUpdating
{
    var searchController: UISearchController?

    let itemList = [ItemList(category:"Chocolate",name:"chocolate Bar",price: 1234),ItemList(category:"Chocolate",name:"chocolate Chip",name:"dark chocolate",ItemList(category:"Hard",name:"lollipop",name:"candy cane",name:"jaw breaker",ItemList(category:"Other",name:"caramel",name:"sour chew",name:"gummi bear",price: 1234)]

    var filteredList : [ItemList] = []

    override func viewDidLoad()
    {
        super.viewDidLoad()

        self.title = "Item Search"
        self.tableView.delegate = self
        self.tableView.dataSource = self

        self.searchController = UISearchController(searchResultsController: nil)
        self.searchController!.searchResultsUpdater = self
        self.searchController!.hidesNavigationBarDuringPresentation = true
        self.searchController!.dimsBackgroundDuringPresentation = false
        self.searchController!.searchBar.searchBarStyle = .Minimal
        self.searchController!.searchBar.sizetoFit()
        self.tableView.tableHeaderView = self.searchController!.searchBar  
    }

    override func prepareForSegue(segue: UIStoryboardSegue,sender: AnyObject?)
    {
        if (segue.identifier == "itemDetail")
        {
            let itemDetailViewController = segue.destinationViewController as UIViewController
            let selectedCell = sender as UITableViewCell
            itemDetailViewController.title = selectedCell.textLabel?.text
        }
    }

    override func tableView(tableView: UITableView,cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
    {
        let cell = self.tableView.dequeueReusableCellWithIdentifier("Cell") as UITableViewCell
        var item : ItemList

        if self.searchController!.active
        {
            item = self.filteredList[indexPath.row]
        }
        else
        {
            item = self.itemList[indexPath.row]
        }

        cell.textLabel!.text = item.name
        return cell
}

    override func tableView(tableView: UITableView,numberOfRowsInSection section: Int) -> Int
    {
        if (self.searchController!.active)
        {
            return self.filteredList.count
        }
        else
        {
            return self.itemList.count
        }
    }
}

extension ItemSearchViewController: UISearchResultsUpdating
{
    func updateSearchResultsForSearchController(searchController: UISearchController)
    {
        if (searchController.searchBar.text.isEmpty)
        {
            self.filteredList = self.itemList
        }
        else
        {
            let searchPredicate =
            {
                (item: ItemList) -> Bool in
                item.name.rangeOfString(searchController.searchBar.text,options: .CaseInsensitiveSearch) != nil
            }
            self.filteredList = self.itemList.filter(searchPredicate)
        }
        self.tableView.reloadData()
    }
}

解决方法

在viewDidLoad()中添加此行

definesPresentationContext = true

来自definesPresentationContext的文档

A Boolean value that indicates whether this view controller’s view is covered when the view controller or one of its descendants presents a view controller.

讨论

When a view controller is presented,iOS starts with the presenting view controller and asks it if it wants to provide the presentation
context. If the presenting view controller does not provide a context,
then iOS asks the presenting view controller’s parent view
controller. iOS searches up through the view controller hierarchy
until a view controller provides a presentation context. If no view
controller offers to provide a context,the window’s root view
controller provides the presentation context.

If a view controller returns true,then it provides a presentation context. The portion of the window covered by the view controller’s view determines the size of the presented view controller’s view. The default value for this property is false.