Which UIViewController properties should I set in -initWithNibName:bundle: vs. -viewDidLoad?

I understand that I should set self.title in 开发者_开发百科-initWithNibName:bundle:.

1. What about self.navigationItem.titleView?

   Since self.navigationItem.titleView seems only to be used when self.view is loaded, I'm thinking I should, to save memory, set self.navigationItem.titleView in -viewDidLoad and nil it in -viewDidUnload, e.g.:

   - (void)viewDidLoad {
       [super viewDidLoad];
       self.navigationItem.titleView = [[UIImageView alloc] initWithImage:
                                        [UIImage imageNamed:@"logo.png"]];
   }
   
   - (void)viewDidUnload {
       self.navigationItem.titleView = nil;
       [super viewDidUnload];
   }
   

2. What about self.navigationItem.backBarButtonItem?

1. It seems to work OK to set self.navigationItem.titleView in -viewDidLoad and nil it in -viewDidUnload.

2. You should set self.navigationItem.backBarButtonItem in -initWithNibName:bundle because if you push two view controllers without animation -viewDidLoad will not get called for the first view controller that's pushed. So, if that view controller sets self.navigationItem.backBarButtonItem in -viewDidLoad, it will actually not get set, and the back button on the second view controller will just default to the title of the first view controller as usual.