iOS中UISearchcontroller和UITablevi

问题描述

在iOS 11以下的版本上，当点击输入框进行搜索，或者不搜索直接点击取消后，上滑页面，搜索框不能正确的弹回，被覆盖在导航栏下面；

问题代码

   override func viewDidLoad() {
        super.viewDidLoad()
        //配置搜索控制器
        uiSearchController = UISearchController(searchResultsController: nil)
        uiSearchController.searchResultsUpdater = self
        uiSearchController.searchBar.placeholder = "请输入名称进行搜索"
        uiSearchController.searchBar.searchBarStyle = .minimal
        uiSearchController.searchBar.sizeToFit()
        uiSearchController.searchBar.returnKeyType = .done
        uiSearchController.hidesNavigationBarDuringPresentation = false
        uiSearchController.dimsBackgroundDuringPresentation = false
        uiSearchController.searchBar.enablesReturnKeyAutomatically = false
        
        if #available(iOS 11.0, *){
            navigationItem.searchController = uiSearchController
            navigationItem.hidesSearchBarWhenScrolling = false
        }else{
            self.tableView.tableHeaderView = uiSearchController.searchBar
            self.automaticallyAdjustsScrollViewInsets = false
        }
    }

正确代码

   override func viewDidLoad() {
        super.viewDidLoad()
        //配置搜索控制器
        uiSearchController = UISearchController(searchResultsController: nil)
        uiSearchController.searchResultsUpdater = self
        uiSearchController.searchBar.placeholder = "请输入名称进行搜索"
        uiSearchController.searchBar.searchBarStyle = .minimal
        uiSearchController.searchBar.sizeToFit()
        uiSearchController.searchBar.returnKeyType = .done
        uiSearchController.hidesNavigationBarDuringPresentation = false
        uiSearchController.dimsBackgroundDuringPresentation = false
        uiSearchController.searchBar.enablesReturnKeyAutomatically = false
        
        if #available(iOS 11.0, *){
            navigationItem.searchController = uiSearchController
            navigationItem.hidesSearchBarWhenScrolling = false
        }else{
            let uiView:UIView = UIView(frame: CGRect(x: 0,y: 0,width: UIScreen.main.bounds.width,height: 45))
            uiView.addSubview(uiSearchController.searchBar)
            self.tableView.tableHeaderView = uiView
            self.automaticallyAdjustsScrollViewInsets = false
        }
    }

下载的官方示例中也存在这个问题，可能一直没有修复；
改正的具体原理不清楚，只是在外面再包了一层view。