Question

I have an UIViewController with several subviews in its view property (UISearchbar and several UIButtons). The UIButtons hooked up to typical IBActions like -(IBAction)buttonPressed:(id)sender for the UIControlEventTouchUpInside state – it doesn’t matter if I do it in IB or programmatically.

- (void)viewDidLoad {
    MUZTitleViewController *title = [[MUZTitleViewController alloc] 
                                     initWithNibName:nil bundle:nil];
    self.navigationItem.titleView = title.view;
}

In my project there’s also an UINavigationController. When I set the navigationItem.titleView of the UINavigationBar to the view of my UIViewControllers view I get an EXC_BAD_ACCESS exception, as soon as I tap one of the button. I don’t know why this is.

I uploaded a small sample project to illustrate my problem: Test010.xcodeproj (it’s ARC enabled)

More and more I come to the conclusion that it’s not a good idea to use the UIViewControllers view and assign it to the titleView but I don’t see any alternative here.

Edit: Sorry, the sample project commented out the call which causes the exception. I reuploaded the linked project file.

Edit^2: As PengOne pointed out I’ve skipped the exact error message I got:

2011-09-10 23:09:50.621 Test010[78639:f803] -[CALayer buttonPressed:]: unrecognized selector sent to instance 0x9254ae0
2011-09-10 23:09:50.623 Test010[78639:f803] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[CALayer buttonPressed:]: unrecognized selector sent to instance 0x9254ae0'

Answer 1

Have you tried setting NSZombieEnabled to YES? If I do this, the console shows the following output:

2011-09-10 22:56:23.329 Test010[6481:ef03] *** -[MUZTitleViewController
performSelector:withObject:withObject:]: message sent to deallocated 
instance 0x7a7ff70

As the project is ARC enabled, the controller seems to get deallocated some time after this line:

MUZTitleViewController *title = [[MUZTitleViewController alloc] initWithNibName:nil bundle:nil];

I am not sure what the best solution is, but a property definitely helps to prevent the exception like so:

// MUZDetailViewController.h
@property (strong, nonatomic) MUZTitleViewController *title;

// MUZDetailViewController.m
@synthesize title;

self.title = [[MUZTitleViewController alloc] initWithNibName:nil bundle:nil];
self.navigationItem.titleView = title.view;