Container View Controller Examples

In addition to the WWDC Session Video Session 102 - Implementing UIViewController Containment that hypercrypt already mentioned, Apple WWDC 2012 session on "The Evolution of View Controllers on iOS" also covers this topic and the example code is part of the sample code package:

https://developer.apple.com/devcenter/download.action?path=/wwdc_2012/wwdc_2012_sample_code/wwdc_2012_session_code.dmg

There's also an example here: https://github.com/toolmanGitHub/stackedViewControllers

The best thing I have found so far is the WWDC 2011 Session Video Session 102 - Implementing UIViewController Containment.

- (void)viewDidLoad{
    [super viewDidLoad];

    // I put self in a Navigation VC so we can use its right navigationbar 
    // item for triggering the transition
    self.navigationItem.rightBarButtonItem = 
     [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemEdit 
                                                    target:self 
                                                    action:@selector(button:)] 
                                                                  autorelease];

    // create test1 and test2 instance (subclass UIViewController and 
    // also need to define their own nibs)
    vc1 = [[test1 alloc]initWithNibName:@"test1" bundle:nil];
    vc2 = [[test2 alloc]initWithNibName:@"test2" bundle:nil];

    //add to the container vc which is self    
    [self addChildViewController:vc1];
    [self addChildViewController:vc2];

    //the entry view (will be removed from it superview later by the api)
    [self.view addSubview:vc1.view];
}

this IBAction triggers the transition between two VCs:

-(IBAction)button:(id)sender {
    [self transitionFromViewController:vc1 
                      toViewController:vc2 
                              duration:0.5    
                               options:UIViewAnimationOptionTransitionCurlDown 
                            animations:nil 
                            completion:nil];
}