viewDidLoad is not called for rootViewController

Question

This is my first iOS project. I'm just following the tutorial from Try iOS over at codeschool in my XCode Application.

I've added a button in my viewDidLoad method. I don't think this is where it would be added normally, but it should still work. The problem is, the method is never called. Here's my code so far:

AppDelegate.m:

    #import "AppDelegate.h"
#import "ViewController.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    //Set window size & background color
    CGRect viewRect = [[UIScreen mainScreen] bounds];
    self.window = [[UIWindow alloc] initWithFrame:viewRect];
    self.viewController = [[ViewController alloc] init];
    UIView *view = [[UIView alloc] initWithFrame:viewRect];
    
    view.backgroundColor = [UIColor yellowColor];
    
    self.viewController.view = view;
    
    self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];
    
    NSLog(@"Screen is %f tall and %f wide", viewRect.size.height, viewRect.size.width);

    return YES;
}...


AppDelegate.h:

#import <UIKit/UIKit.h>

@class ViewController;

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) ViewController *viewController;

@end



ViewController.m:

    #import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor blueColor];
    
    UIButton *firstButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    firstButton.frame = CGRectMake(100, 100, 100, 44);
    [firstButton setTitle:@"Don't Click!" forState:UIControlStateNormal];
    [self.view addSubview:firstButton];
}...

When the app is up and running, my background remains yellow, and there is no button visible.

Stepping through the application, didFinishLaunchingWithOptions: hits as I expected. When the view is initializes, I expect the viewDidLoad to run. I may just be misunderstanding the way C "sends messages".

If any additional information might help please let me know. Thanks for any help :)

EDIT

Does this have something to do with storyboarding? I'm in storyboard mode but I never added any button using the GUI

Answer 1

... self.viewController.view = view; ...

You shouldn't set viewController's view before viewDidLoad, which cause viewDidLoad not called. View should be set in viewDidLoad, and the viewController's will manage its view automatically for you.

Answer 2

viewDidLoad is not being called because of the non-standard way that you're creating its view. Usually, the view is loaded from a xib or storyboard, or created in code in the loadView method of the view controller -- in all these cases, viewDidLoad will be called. If you move your view creation to loadView in the controller's .m file, it will work, and viewDidLoad will be called.

After Edit:

If you're using a storyboard, your view should be created there, and you shouldn't be doing what you're doing in the app delegate. In fact, when you use a storyboard, you don't normally have any code in the application:didFinishLaunchingWithOptions: method.