Question

I’m new with iOS development, but I’m familiar with the memory management basics in Obj-C. However, Apple’s docs about custom UIViewControllers confused me a bit.

So, I have a PagingController that stores an array of EntryViewController objects. (They’re all UIViewControllers.) These objects are loaded dynamically and, of course, released when appropriate. The view in PagingController is created in -loadView and stored in self.view, just as the documentation said.
Whenever I load an EntryViewController (as ctrl), I call [self.view addSubview:ctrl.view];. I also need to call ctrl.parent = self; since the target OS is 3.0 and I don’t want to modify a private variable (_parentViewController). (parent is defined as @property(assign) PagingController *parent;)

Here are my questions:

1. Do I have to release self.view myself, or is UIViewController taking care of that?
2. Do I have to retain parent (the property in EntryViewController)? I assume it’s pointless, since all the child view controllers are being released when the parent is unloaded.
3. Do I have to call [self.view removeFromSuperview] in the -dealloc method of EntryViewController? The docs said, I have to manage all of the subviews, so I’m not sure if this gets called automatically.

Or am I just confused about how to create a custom view controller in the first place?

Answer 1

1. UIViewController will take care of that
2. You shouldn’t retain parent, set the property to assign, otherwise you’re gonna have a retain cycle
3. The view controller will take care its view, you only need to release the other subviews you are retaining (removeFromSuperview isn’t necessary)