The Core iOS Developer’s Cookbook, Fifth Edition

Adding and Removing a Child View Controller

In the simplest scenario, adding a child to a container controller takes three steps:

1. Call addChildViewController: on the parent and pass the child as the argument (for example, [self addChildViewController:childvc]).

2. Add the child controller’s view as a subview (for example, [self.view addSubview:childvc.view]).

3. Call didMoveToParentViewController: on the child with the parent as its argument (for example, [childvc didMoveToParentViewController:self]).

To remove a child view controller, the steps are almost (but not quite) mirrored:

1. Call willMoveToParentViewController: on the child, passing nil as the argument (for example, [childvc willMoveToParentViewController:nil]).

2. Remove the child ...