Hide/Show back button on Navigation Bar when Search Bar opens/closes - ios

Question

So I have a navigation bar that has a "Back" button on it and a UISearchBar to the right of this:
![enter image description here][1]
When the UISearchBar opens/shows, the cancel button hides/shows:
![enter image description here][2]
What I want is when the UISearchBar opens, I want it to basically "cover" the back button. When it closes, I want it so "uncover" the back button. Here is my code so far:
#import "SearchViewController.h"
#interface SearchViewController ()
#end
- (void)viewDidLoad {
[super viewDidLoad];
if ([self respondsToSelector:#selector(edgesForExtendedLayout)])
self.edgesForExtendedLayout = UIRectEdgeNone;
UISearchBar *searchBar = [UISearchBar new];
searchBar.showsCancelButton = NO;
[searchBar sizeToFit];
searchBar.delegate = self;
self.navigationItem.titleView = searchBar;
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:nil style:UIBarButtonItemStylePlain target:self action:nil];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar
{
[searchBar setShowsCancelButton:YES animated:YES];
}
- (void)searchBarTextDidEndEditing:(UISearchBar *)searchBar
{
[searchBar setShowsCancelButton:NO animated:YES];
}
- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar
{
[searchBar resignFirstResponder];
[searchBar setShowsCancelButton:NO animated:YES];
}
#end
What I've tried was to do: self.navigationItem.hidesBackButton = NO/YES; in the searchBarTextDidBeginEditing/searchBarTextDidEndEditing but this leaves the spot where the back button was empty:
![enter image description here][3]
Is there a way I can have the search bar extend over the back button? Thanks!

Answer 1

Try to do it by
self.navigationItem.leftBarButtonItem=nil;
self.navigationItem.hidesBackButton=YES;
or
self.navigationItem.backBarButtonItem=nil;
Updated code :
#interface SearchViewController ()
{
UIBarButtonItem *backButtonItem;
UIBarButtonItem *negativeSpacer;
}
#end
#implementation SearchViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
UISearchBar *searchBar = [UISearchBar new];
searchBar.showsCancelButton = NO;
[searchBar sizeToFit];
searchBar.delegate = self;
self.navigationItem.titleView = searchBar;
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:nil style:UIBarButtonItemStylePlain target:self action:nil];
self.navigationItem.backBarButtonItem=nil;
self.navigationItem.hidesBackButton=YES;
UIButton *backButton = [[UIButton alloc] initWithFrame: CGRectMake(0, 0, 70.0f, 21.0f)];
UIImage *backImage = [UIImage imageNamed:#"Back.png"];
[backButton setImage:backImage forState:UIControlStateNormal];
[backButton setTitleEdgeInsets:UIEdgeInsetsMake(10.0, 10.0, 10.0, 0.0)];
[backButton setTitle:#"Back" forState:UIControlStateNormal];
[backButton addTarget:self action:#selector(backButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
backButtonItem = [[UIBarButtonItem alloc] initWithCustomView:backButton];
negativeSpacer = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
[negativeSpacer setWidth:-15];
self.navigationItem.leftBarButtonItems = [NSArray arrayWithObjects:negativeSpacer,backButtonItem,nil];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar
{
[searchBar setShowsCancelButton:YES animated:YES];
self.navigationItem.leftBarButtonItems = nil;
}
- (void)searchBarTextDidEndEditing:(UISearchBar *)searchBar
{
[searchBar setShowsCancelButton:NO animated:YES];
}
- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar
{
[searchBar resignFirstResponder];
[searchBar setShowsCancelButton:NO animated:YES];
self.navigationItem.leftBarButtonItems = [NSArray arrayWithObjects:negativeSpacer,backButtonItem,nil];
}
- (IBAction)backButtonPressed:(id)sender{
[self.navigationController popViewControllerAnimated:YES];
}