使用导航栏上的Back错误UIBarButtonItem

Question

I have a NavigationBar at the top of a TableView. It looks nice opening/closing the search.

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However, if I click on a button in a cell and get directed to another page (with segue); and then use Back button to unwind, it seems like bugged.

( )

So it looks like it is pressed and opened but it shouldn't have. It should be looked like the top picture instead (just UIBarButtonItem - search button)

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I couldn't figure out the issue creating this problem.

Please note that < Back is created automatically and I didn't write any code to create it. Is there something I am doing wrong?

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Update: Added some snippets...

First, created a different class for handling the search

class SearchBarViewController: UIViewController, UISearchBarDelegate {

  var searchBar : UISearchBar?
  var searchBarWrapper : UIView?
  var searchBarButtonItem : UIBarButtonItem?

  func constructSearchBar()
  {
     searchBarButtonItem = UIBarButtonItem(barButtonSystemItem: .Search, target: self, action: "showSearchBar")
     self.navigationItem.rightBarButtonItem = searchBarButtonItem
  }

  func showSearchBar() {
          // styling & configuration
   }

  func searchBarCancelButtonClicked(searchBar: UISearchBar) {

     UIView.animateWithDuration(0.2, animations: {
         self.searchBar?.resignFirstResponder()
         self.searchBarWrapper?.alpha = 0
         }, completion: { (success) -> Void in
             self.searchBar = nil
             self.searchBarWrapper = nil
             self.navigationItem.rightBarButtonItem = self.searchBarButtonItem
        })
    }
   }

And my ViewController:

 class ViewController: SearchBarViewController {

   override func viewDidLoad() {
      super.viewDidLoad()
      constructSearchBar()
   } 
 }

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Regarding to emrys57 's answer, I tried adding viewWillAppear() in my ViewController but I couldn't make it work, as my cancel looks a little different:

override func viewWillAppear(animated: Bool) {
    super.viewDidAppear(animated)

    // Here, I couldn't figure out what to put because
    // my searchBarCancelButtonClicked() needs searchBar and
    // forces me to use (!) but then it says, it's optional..
}

---

The answer is...

 override func viewWillAppear(animated: Bool) {
    super.viewDidAppear(animated)
    navigationItem.titleView = nil
    constructSearchBar()
 }

Answer 1

You have not posted code, so it's not entirely clear what's gone wrong. Using UISearchBar , I think you must be handling the buttons separately yourself, as opposed to using UISearchController . I think that you may not be clearing away the search bar when coming back from the second VC. This code clears out the search bar in viewWillAppear :

class ViewController: UIViewController {

var cancelButton: UIBarButtonItem?
var searchButton: UIBarButtonItem?

override func viewDidLoad() {
    super.viewDidLoad()
    cancelButton = UIBarButtonItem(barButtonSystemItem: .Cancel, target: self, action: Selector("searchCancelPressed:"))
    searchButton = UIBarButtonItem(barButtonSystemItem: .Search, target: self, action: Selector("searchPressed:"))
}

override func viewWillAppear(animated: Bool) {
    super.viewDidAppear(animated)
    searchCancelPressed(nil)
}

func searchPressed(sender: AnyObject) {
    navigationItem.titleView = UISearchBar()
    navigationItem.rightBarButtonItem = cancelButton
}

func searchCancelPressed(sender: AnyObject?) {
    navigationItem.titleView = nil
    navigationItem.rightBarButtonItem = searchButton
}

}

and that is working nicely for me when I do a push from a button to the second VC and then hit back .

Following the edit to the original question, this code seems to work, although it may not be the most elegant way of constructing the answer:

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
    navigationItem.titleView = nil
    searchBarButtonItem = UIBarButtonItem(barButtonSystemItem: .Search, target: self, action: "showSearchBar")
    navigationItem.rightBarButtonItem = searchBarButtonItem
}

The function constructSearchBar no longer needs to be called in viewDidLoad , and can be deleted.