iphone - Can you swap the NIB file for a UIViewController that's already on-screen?

Question

For instance:

1. Create a new UIVC using initWithNibName, using "nib-v1"
2. Display it, e.g. using [(UINavigationController) nav pushViewController: myVC]
3. Change the NIB that myVC is using to "nib-v2"

So far as I can see, this is the "correct" approach to app-design for a lot of apps, when paging through information where you need two slightly different UI screens for the info being displayed.

For instance, most of your pages are text, but some of them have an image too (think of an RSS reader, where some RSS entries have text + image, some are text only).

I've dealt with this previously by having one NIB file with a second, invisible, named UIView instance that I layered over the top of the first one, and switched on/off depending on on context, using the "hidden" flag.

But this is clearly wrong, and wastes memory.

However, I cannot see an obvious way to "reload" the view from the NIB file. I'm guessing I want to somehow reproduce the magic that initWithNibName does?

I suspect this is possible, but I'm sure that if you do it "the wrong way" then the app will simply crash horribly.

Answer 1

You can always perform

[[NSBundle mainBundle] loadNibNamed:@"FileName" owner:viewController options:nil]];

but this will undoubtedly really mess things up, if you're not sure what you're doing, especially if view is connected in both of those nibs

You should redesign your view controller hierarchy to swap between two different controllers that load from two different nib files.

---

Alternately, you can have the controller manage swapping views that it loads from different files that are unrelated to it's nibName. In that case, you can load them in the above manner. And you will want to have their outlets (to, for example, subviewOne and subviewTwo) connected in different nibs.