Question

Why doesn’t this work? I want to sublcass UINavigationBar so in xcode I click new file -> objective c class,
class: CustomNavBar
subclass of: UINavigationBar

then in the storyboard under the navigation controller scene, I click on the Navigation Bar and set it’s class to CustomNavBar.

I then go into my CustomNaVBar class and have tried to add a custom image background.

In the initWithFram method I have added this:

- (id)initWithFrame:(CGRect)frame
{
    NSLog(@"Does it get here?"); //no
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        UIImage *image = [UIImage imageNamed:@"customNavBarImage.png"];
        //  [self setBackgroundImage:image forBarMetrics:UIBarMetricsDefault];
        [self setBackgroundColor:[UIColor colorWithPatternImage:image]];
        [[UINavigationBar appearance] setBackgroundImage:image forBarMetrics:UIBarMetricsDefault];
        NSLog(@"Does this get called?"); //no
    }
    return self;
}

I don’t see any output on the console.

Instead I have done this to customize the UINavBar, but I feel like it isn’t as correct as sublassing it. In my first view’s viewDidLoad I added this line:

- (void)viewDidLoad
{
    [super viewDidLoad];
    if ([self.navigationController.navigationBar respondsToSelector:@selector(setBackgroundImage:forBarMetrics:)] ) {
        UIImage *image = [UIImage imageNamed:@"customNavBarImage.png"];
        [self.navigationController.navigationBar setBackgroundImage:image forBarMetrics:UIBarMetricsDefault];
    }
}

Answer 1

I agree with Ryan Perry. In addition to his answer:

You should not put this code in initWithFrame, instead put your code in awakeFromNib

- (void) awakeFromNib {
    // Initialization code
    UIImage *image = [UIImage imageNamed:@"customNavBarImage.png"];
    //  [self setBackgroundImage:image forBarMetrics:UIBarMetricsDefault];
    [self setBackgroundColor:[UIColor colorWithPatternImage:image]];
    [[UINavigationBar appearance] setBackgroundImage:image forBarMetrics:UIBarMetricsDefault];
    NSLog(@"Does this get called?"); //YES!!
}