Question

I’ve seen apps that have views that you swipe and it just slides to the next one, and it moves according to how far you’ve swiped. Kind of like a film strip. Is there an easy way to do this?

Answer 1

You can use a UIScrollView to achieve precisely this effect. (Each “picture” in the film strip being a view that you add to the scroll view.)

Incidentally, the above linked class reference document also contains links to sample code – see the “Related sample code” section in the header.

UPDATE

Here’s some sample code to detect the “current” page. It’s been a while since I’ve used a UIScrollView (this is from an early “getting to know iOS” plaything I wrote), so this may not be the best solution.

// Calculate which page is visible  
CGFloat pageWidth = scrollView.frame.size.width;
int currentPage = floor((scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;