Question

I’m trying to use a UINavigationController but I’m uncertain how. Up till now (for about a year), I’ve been using presentModalViewController and dismissModalViewController to present/dismiss view controllers.

So, this is what I did. My main view controller (the first one that shows on launch) is called MainViewController, and it extends UIViewController.

So I made this launch function in my app delegate:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    

    MainViewController *controller = [[MainViewController alloc] init];
    UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:controller];  
    [self.window addSubview:navigationController.view];  
    [self.window makeKeyAndVisible];

    return YES;
}

And in my MainViewController’s viewDidLoad method:

- (void)viewDidLoad {

        [super viewDidLoad];

        self.title = @"Title";
        self.navigationController.navigationBar.tintColor = [Constants barColor];

            ....more code...
    }

But, in my MainViewController, I’d like to present another view controller called SecondViewController, which needs a UINavigationBar with a back arrow button. So do I make SecondViewController extend UIViewController and do the same thing by setting the title and backButton in the viewDidLoad method? And how do I present it? What should I do to accomplish this?

Answer 1

You’ll need to set a root view controller up, it’s easiest starting from the apple template.

Here’s where the magic happens:

UIViewController *controller = [[UIViewController alloc] initWithNibName:@"MyNib" bundle:nil];
[self.navigationController pushViewController:controller animated:YES];
[controller release];

The nav controller does all the work for you (back buttons, titles, animations) – it keeps track!

---

My workflow is this:

Setup MutableArray in the viewDidLoad, add controllers to it, e.g:

NSMutableArray *array = [[NSMutableArray alloc] init];
MyCustomViewController *customView = [[MyCustomViewController alloc] initWithNibName:@"nib" bundle:@"nil"];
customView.title = @"Second Level";
[array addObject:customView];
self.controllers = array;

Then in your delegate:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSUInteger row = [indexPath row];
    UIViewController *childControllerToBe = [controllers objectAtIndex:row];
    [self.navigationController pushViewController:childControllerToBe animated:YES];
}

This, along with a lot more can be learnt by reading a decent beginner book such as Beginning iPhone Development

Also, apple docs are always good 🙂