set custom back bar button universally with no title

Question

I want to set custom back bar button for all controllers in the app. I tried using this:

[[UIBarButtonItem appearance] setBackButtonBackgroundImage:backB

Answer 1

I've resolved it. Just make a category over UIViewController and import it in prefix.pch file. Then write a method: customViewWillAppear: and swizzle it with viewWillAppear method:

+(void)load{

Method viewWillAppear = class_getInstanceMethod(self, @selector(customViewWillAppear:));

Method customViewWillAppear = class_getInstanceMethod(self, @selector(viewWillAppear:));
method_exchangeImplementations(viewWillAppear, customViewWillAppear);

}

Add the above method to that category class. Then implement your customViewWillAppear method like this:

-(void)customViewWillAppear:(BOOL)animated{
    [self customViewWillAppear:animated];
    if([self.navigationController.viewControllers indexOfObject:self] != 0  && !self.navigationItem.hidesBackButton){
        UIBarButtonItem *cancelBarButton = nil;
        UIButton* cancelButton = [UIButton buttonWithType:UIButtonTypeCustom];
        [cancelButton addTarget:self action:@selector(popViewControllerWithAnimation) forControlEvents:UIControlEventTouchUpInside];
        [cancelButton setBackgroundImage:[UIImage imageNamed:@"yourImage.png"] forState:UIControlStateNormal];
        [cancelButton sizeButtonToFit];

        cancelBarButton = [[UIBarButtonItem alloc] initWithCustomView:cancelButton];

        NSMutableArray * leftButtons = [NSMutableArray arrayWithObject:cancelBarButton];
        [leftButtons addObjectsFromArray:self.navigationItem.leftBarButtonItems];
        [self.navigationItem setLeftBarButtonItem:nil];
        [self.navigationItem setLeftBarButtonItems:leftButtons];
    }

    [self.navigationItem setHidesBackButton:YES];
}
-(void)popViewControllerWithAnimation{
    [self.navigationController popViewControllerAnimated:YES];
}

Now, for every controller in your code, you have a custom back button. This took me a lot of time to implement and figure out. Hope it'll help you guys all too.

EDIT: Please use the following code to support iOS7> back swipe feature;

UIImage *image = [UIImage imageForName:@"some_image"];
navBar.backIndicatorImage = [image imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
navBar.backIndicatorTransitionMaskImage = [image imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];

Create a base view controller and add the following code;

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];
}