How to present a (no nib) ViewController - objective-c

Question

I've created a ViewController (without nib files), so how do I load this viewController in the app delegtate? my current code is:
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
viewController = [[MyCustomViewController alloc] init...]; // I use a custom init method
self.window.rootViewController = self.viewController;
[self.window makeKeyAndVisible];
return YES;
And how can I use the presentModalViewController method to show new view controllers of the same "CustomViewController" class?
THANKS for the help!
NOTE: By the way, I do see that this code does call my initialization method, and my ViewDidLoad method in my customViewController is being called however the screen is still black....

Answer 1

It looks like your properties are not set up correctly.
Check this line:
viewController = [[MyCustomViewController alloc] init...]; // I use a custom init method
self.window.rootViewController = self.viewController;
check that self.viewController is okay, and there's nothing stopping you from just doing:
self.window.rootViewController = viewController;

Answer 2

Whoops, I was just missing this code in my viewDidLoad Method:
self.view.frame = CGRectMake(0, 0, 320, 480);
self.view.backgroundColor = [UIColor whiteColor];
So everything was working, but the screen by default is black and without a frame.

Answer 3

I had to do just that in one of the apps I'm working on. Try typecasting your view controller
CDViewController *viewController = (CDViewController*)self.window.rootViewController;
viewController.managedObjectContext = self.managedObjectContext;
viewController.managedObjectModel = self.managedObjectModel;
// Override point for customization after application launch.
return YES;