rightBarButtonItem在iOS-9和iOS-10中弹出时消失

Question

我已经阅读了多篇关于此的帖子，但无法使其正常运行。

我已经读过的帖子：

1. Custom rightBarButtonItem disappearing
2. RightBarButtonItem disappears when view appears again

我在ViewController-A中嵌入了UINavigationController。控制器的navigation bar包含rightBarButtonItem。添加rightBarButtonItem的代码：

let searchButton = UIBarButtonItem(image: UIImage(named: "HomeSearch"), style: .plain, target: self, action: #selector(navigateToSearchScreen))
self.navigationItem.rightBarButtonItem = searchButton

当另一个ViewController-B被推入导航堆栈并弹回时，rightBarButtonItem将从导航栏中消失。

Answer 1

我认为在nextViewcontroller中你隐藏了导航右栏，所以当你弹出然后导航按钮将不会显示所以你必须在viewWillAppear中添加右栏按钮：

override func viewWillAppear(_ animated: Bool) {
        let searchButton = UIBarButtonItem(image: UIImage(named: "HomeSearch"), style: .plain, target: self, action: #selector(navigateToSearchScreen))
        self.navigationItem.rightBarButtonItem = searchButton
    }