navigationItem.set_BarButton 不起作用 - swift

Question

我正在实施一个隐藏的搜索栏。

一切正常，除了在隐藏搜索栏的函数中恢复栏按钮的命令。

此外，UISearchBar.showCancelButton 也不起作用，所以我不得不手动实现取消按钮。（我已经将搜索栏的委托设置为自己）

代码如下：

func dismissSearch() {
    searchBar.text = ""
    view.endEditing(true)
    tagSearchResults = [Tag]()
    TagSearchFeed?.collectionView.reloadData()
    searchResultsContainer.isHidden = true
    hideSearchBar() 
}



func showSearchBar() {
    searchBar.alpha = 0
    navigationItem.titleView = searchBar
    let cancelButton = UIBarButtonItem(title: "Cancel", style: .plain, target: self, action: #selector(searchBarCancelButtonClicked))
    cancelButton.tintColor = .white
    navigationItem.setRightBarButton(cancelButton, animated: true)
    navigationItem.setLeftBarButton(nil, animated: true)
    UIView.animate(withDuration: 0.5, animations: {
        self.searchBar.alpha = 1
    }, completion: { finished in
        self.searchBar.becomeFirstResponder()
    })
    self.searchResultsContainer.isHidden = false
}

func hideSearchBar() {
    navigationItem.setRightBarButton(self.searchButton, animated: true)
    navigationItem.setLeftBarButton(self.menuButton, animated: true)
    UIView.animate(withDuration: 0.3, animations: {
        self.navigationItem.titleView = nil
    }, completion: { finished in

    })

}

@objc func searchBarCancelButtonClicked() {
    dismissSearch()
}

我该如何解决这些问题？

Answer 1

原来那些bar buttons item是nil，我把outlets改成了strong，现在可以用了。来自：

@IBOutlet var weak searchButton: UIBarButtonItem!
@IBOutlet var weak menuButton: UIBarButtonItem!

收件人：

@IBOutlet var searchButton: UIBarButtonItem!
@IBOutlet var menuButton: UIBarButtonItem!

navigationItem.set_BarButton 不起作用 - swift

navigationItem.set_BarButton does not work - swift

uisearchbar

uinavigationitem

ios

swift