Why is my initWithNibName method returning a nil view?

Question

I'm calling this method when trying to present a new view controller. The commented out lines are the other things I've tried with no success.

-(void)presentMailBoxViewController{
    TPMailBoxViewController* mailBoxViewController=[[TPMailBoxViewController alloc]initWithNibName:@"TPMailBoxViewController" bundle:nil];
    [self.navigationController pushViewController:mailBoxViewController animated:YES];
    //[self.navigationController presentViewController:mailBoxViewController animated:YES completion:NULL];
    //[self presentViewController:mailBoxViewController animated:YES completion:NULL];
}

I've set the file owner as my corresponding view controller.

I've even linked the view object of my xib into my view controller as a property.

But, when I break on [self.navigationController pushViewController:mailBoxViewController animated:YES];

The view property of the view controller is nil. What gives?

Answer 1

A project clean and this one line change in my presentMailBoxViewController fixed my issue. Still would like to know why though. Thanks everyone!

-(void)presentMailBoxViewController{
    TPMailBoxViewController* mailBoxViewController=[[TPMailBoxViewController alloc]initWithNibName:@"TPMailBoxViewController" bundle:nil];
    [self presentViewController:mailBoxViewController animated:YES completion:NULL];
}

Answer 2

In your AppDelegate, you need to set the root object of the window as the navigation controller. You can do it like this:-

YourViewController *rootObj = [[LoginViewController alloc] init];
 UINavigationController *navObj = [[UINavigationController alloc] initWithRootViewController:rootObj];

[self.window setRootViewController:navObj];

self.window.backgroundColor = [UIColor whiteColor];
[self.window makeKeyAndVisible];

After this, try pushing the viewcontroller, it should work

Answer 3

"UIViewController" already has a "view" property, so you don't need "myView".

Open up your storyboard or XIB file and make certain that the "view" that you want to be displayed with your is connected in your storyboard or XIB file to your TPMailBoxViewController object.

Right after you "initWithNibName", the view controller object exists but its "view" property is likely to be nil because the view has not been loaded yet.

It's when you push the view controller, that is when your "TPMailBoxViewController" will get the "viewWillLoad" and "viewWillAppear" methods being called and when the view is loaded, the "view" outlet will change from nil to something real.