当在视图中重新加载资源时方向发生变化？

Question

I have view that have many subviews, and each have it's own graphics, different for portrait and landscape orientations. When should I load the new graphics when the orientation changes?

If shouldn't be layoutSubviews, I don't also like the idea of reloading resources in view from UIViewController, because of complicated view hierarchy that I have (it would require to pass this information down).

There is also option to register in NSNotificationCenter for orientation changes in each view, and load new resources when it changes. But I don't quite like it either, because I believe that there should be mechanism in iOS that enables that. Or, maybe I should think in a different way, and build different views for portrait and landscape...

What do you suggest?

Answer 1

I would have your subviews all extend a custom view class that has a -setOrientation: method that swaps between the portrait and landscape graphics. Then in your view controller I would override -willRotateToInterfaceOrientation:duration: and add a loop that sets the orientation for all of the children, thereby causing the graphics to swap when the orientation changes.

I think that's the most straighforward way to do it. Using NSNotificationCenter could be tricky and you're left without a guarantee that every child will get the notification.

Anyway, that's how I'd do it. Let me know if you need examples.