self.navigationItem.backBarButtonItem cannot be set - ios

Question

I have a TableViewController named TVC and a cell in it. When I clicked on cell, TableViewController will push a new ViewController (VC) into its navigation controller. In this case, I set the [self.navigationItem.backBarButtonItem setTitle:#" "] in the viewDidLoad function of the TVC. But in the new pushed ViewController VC, the back button still has the "back" text. Can anyone explain this?
BTW, the TableViewController TVC is also pushed by another view controller VC2. I set the same function [self.navigationItem.backBarButtonItem setTitle:#" "] in the viewDidLoad function of the VC2 and the back button text displayed in the TVC is correctly hidden.

Answer 1

What Bimala and Ted pointed are two ways of approaching the issue. The former is to set a custom BackButtonItem and the latter is to simply use the default BackButton. But setting the title of the screen to "" may not always be acceptable. So u can choose to do the same in ViewWillDisappear method.
OBJ C:
-(void) viewWillDisappear:(BOOL)animated{
self.navigationItem.title = #"";
[super viewWillDisappear:animated];
}
SWIFT:
override func viewWillDisappear(animated: Bool) {
self.title = ""
super.viewWillDisappear(true)
}
Also you can set the title back in ViewWillappear
OBJ C:
-(void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
self.navigationItem.title = #"your title";
}
SWIFT:
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(true)
self.title = "your title"
}

Answer 2

That's because the back button takes the title of the previous view controller. When none set it defaults to back. So set the name of the TableViewController to an empty string as follows:
override func viewDidLoad() {
super.viewDidLoad()
self.navigationItem.title = ""
}

Answer 3

Its my example:
UIView *leftView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 30, 30)];
[leftView setBackgroundColor:[UIColor clearColor]];
UIButton *leftViewButton = [UIButton buttonWithType:UIButtonTypeCustom];
[leftViewButton setFrame:CGRectMake(0, 0, 30, 30)];
[leftView addSubview:leftViewButton];
[leftViewButton setImage:[UIImage imageNamed:#"NavigationBarButtonBackDefault"] forState:UIControlStateNormal];
[leftViewButton setImage:[UIImage imageNamed:#"NavigationBarButtonBackPressed"] forState:UIControlStateHighlighted];
UIBarButtonItem *barButtonItemLeft = [[UIBarButtonItem alloc] initWithCustomView:leftView];
self.navigationItem.leftBarButtonItem = barButtonItemLeft;
from documentation:
If the title of your back button is too long to fit in the available space on the navigation bar, the navigation bar may substitute the string “Back” in place of the button’s original title. The navigation bar does this only if the back button is provided by the previous view controller. If the new top-level view controller has a custom left bar button item—an object in the leftBarButtonItems or leftBarButtonItem property of its navigation item—the navigation bar does not change the button title.

Answer 4

If you just want to hide Back button then try:
self.navigationItem.hidesBackButton = YES;
or
self.navigationController.navigationBar.topItem.hidesBackButton = YES;
If you want to set custom Back button then use:
UIBarButtonItem *barButtonItem = [ [UIBarButtonItem alloc] initWithTitle: #"Custom"
style: UIBarButtonItemStylePlain
target: nil action: nil];
self.navigationController.navigationBar.topItem.backBarButtonItem = barButtonItem;