Ios 如何将UITableView的顶部粘贴到UISearchBar的底部?

Ios 如何将UITableView的顶部粘贴到UISearchBar的底部?,ios,swift,constraints,Ios,Swift,Constraints,我的观点是: tableView = UITableView() tableView.dataSource = self tableView.delegate = self tableView.register(UINib(nibName: "TableViewCell", bundle: nil), forCellReuseIdentifier: "Cell") tableView.rowHeight = 60.0

我的观点是:

tableView = UITableView()
        tableView.dataSource = self
        tableView.delegate = self
        tableView.register(UINib(nibName: "TableViewCell", bundle: nil), forCellReuseIdentifier: "Cell")
        tableView.rowHeight = 60.0
        tableView.tableFooterView = UIView()
        view.addSubview(tableView)

        tableView.translatesAutoresizingMaskIntoConstraints = false

        tableViewHeightAnchor = tableView.heightAnchor.constraint(equalToConstant: 0)
        let constraints = [tableView.topAnchor.constraint(equalTo: view.topAnchor), tableView.leadingAnchor.constraint(equalTo: view.leadingAnchor), tableView.trailingAnchor.constraint(equalTo: view.trailingAnchor), tableViewHeightAnchor!]
        NSLayoutConstraint.activate(constraints)
我的搜索栏是:

    searchController = UISearchController(searchResultsController: nil)
    searchController.searchResultsUpdater = self
    searchController.searchBar.delegate = self
    searchController.obscuresBackgroundDuringPresentation = false
    searchController.searchBar.placeholder = "Search for a cell"
    navigationItem.searchController = searchController
    definesPresentationContext = true
但我希望我的首要目标是:

tableView.topAnchor.constraint(equalTo: searchController.searchBar.bottomAnchor)
但不是:

tableView.topAnchor.constraint(equalTo: view.topAnchor)
但当我把它粘在搜索栏的底部锚上时,应用程序会因为不同的层次结构而崩溃

'Unable to activate constraint with anchors <NSLayoutYAxisAnchor:0x6000017a6cc0 "UITableView:0x7f81c4876e00.top"> and <NSLayoutYAxisAnchor:0x6000017a6dc0 "_UISearchControllerView:0x7f81c2d3fa30.bottom"> because they have no common ancestor.  Does the constraint or its anchors reference items in different view hierarchies?  That's illegal.'
“无法使用锚激活约束,因为它们没有共同的祖先。”。约束或其锚定是否引用不同视图层次中的项?这是违法的。”
我怎样才能解决这个问题? 我试图解决这个问题已经3天了,但没有成功

选项A(导航栏中的搜索栏):

选项B(搜索栏作为表格标题视图):


你能展示一下你想要达到的目标吗?如果您将搜索栏放入导航栏(如您的示例中),将表视图固定到视图是正确的。谢谢!问题似乎出在没有使用
safeArea
let tableView = UITableView()
view.addSubview(tableView)

let searchController = UISearchController(searchResultsController: nil)
navigationItem.searchController = searchController

definesPresentationContext = true

tableView.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
    tableView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
    tableView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
    tableView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor),
    tableView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
])
let tableView = UITableView()
view.addSubview(tableView)

let searchController = UISearchController(searchResultsController: nil)
tableView.tableHeaderView = searchController.searchBar

definesPresentationContext = true

tableView.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
    tableView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
    tableView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
    tableView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor),
    tableView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
])