iOS App view and navigation design custom class - iphone

Question

In my iOS App I have the below code snipped repeating over and over again in every class.
I have tried to cast the method into a NSObject class but I receive errors for the use of "navigationItem".
-(void)customDesign {
//background pattern
self.view.backgroundColor = [[UIColor alloc] initWithPatternImage:[UIImage imageNamed:#"BG-pattern.png"]];
// nav bar
[self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:#"top_bar.png"] forBarMetrics:UIBarMetricsDefault];
//back button color #2974c3
[self.navigationController.navigationBar setTintColor:[UIColor colorWithRed:41.0/255.0f green:116.0/255.0f blue:195.0/255.0f alpha:1.0]];
//settings button
UIImage* settingsImage = [UIImage imageNamed:#"ButtonMenu.png"];
CGRect frameimg = CGRectMake(0, 0, settingsImage.size.width, settingsImage.size.height);
UIButton *uiSettingsButton = [[UIButton alloc] initWithFrame:frameimg];
[uiSettingsButton setBackgroundImage:settingsImage forState:UIControlStateNormal];
[uiSettingsButton addTarget:self action:#selector(menuButton) forControlEvents:UIControlEventTouchUpInside];
[uiSettingsButton setShowsTouchWhenHighlighted:YES];
//add buton to navbar
UIBarButtonItem *settingsButton = [[UIBarButtonItem alloc] initWithCustomView:uiSettingsButton];
self.navigationItem.leftBarButtonItem = settingsButton;
}

Answer 1

You should be creating your own subclass of UIViewController or UITableViewController (whichever you're using) and place this code in your viewDidLoad method of that subclass. All the controllers that need this code can then extend your custom class. This will save you the hassle of having to write this code everywhere.
Your custom subclass:
#interface CustomViewController : UIViewController
#end
Your viewDidLoad method in the subclass:
#implementation CustomViewController
- (void)viewDidLoad {
[super viewDidLoad];
// all your custom code here...
}
#end
Extend your custom class for controllers you want to have common stuff done in:
#interface VisuallyChangedViewController : CustomViewController
#end
#implementation VisuallyChangedViewController
- (void)viewDidLoad {
[super viewDidLoad];
}
#end