如何从视图和更新UI中删除iOS 11搜索栏

Question

在Xcode9中，当我将搜索栏放在视图中时，它会自动向下移动UI的其余部分。当我试图从视图中删除搜索栏时，我得到一个黑色空格，而不是正在更正的UI。我使用的行是: self.navigationItem.searchController = nil。我尝试了很多东西，但我不知道如何纠正用户界面后，搜索栏被删除。只有当我移动到另一个视图控制器并返回时，UI才会在没有搜索栏的情况下再次正确。这里我漏掉了什么？

代码：

@IBAction func searchIconPressed(_ sender: UIBarButtonItem) {

    //ios 11
    if #available(iOS 11.0, *) {
         if self.navigationItem.searchController == nil {
            self.navigationItem.searchController = self.searchController
            self.searchController.isActive = true

        }
        else {
            self.navigationItem.searchController?.isActive = false
            self.navigationItem.searchController = nil
        }
    }
    //when ios 9-10
    else {
        if self.navigationItem.titleView == nil {
            self.navigationItem.titleView = self.searchController.searchBar
            self.searchController.isActive = true
        }
        else {
            self.navigationItem.titleView = nil
        }
    }
}

}

Answer 1

从视图中删除搜索栏并使UI再次上移的答案：

self.navigationItem.searchController?.isActive = false
let search = UISearchController(searchResultsController: nil)
self.navigationItem.searchController = search
self.navigationItem.searchController = nil

Answer 2

这里是目标C

[self.navigationItem.searchController setActive:NO];
UISearchController *nilSearch = [[UISearchController alloc] initWithSearchResultsController:nil];
self.navigationItem.searchController = nilSearch;
self.navigationItem.searchController = nil;