How to make iOS App background change with scrolling up/down

Question

I'm trying to make the background and text change as the user scrolls up or down. Similar to what Apple uses on their website pages like this http://www.apple.com/iphone/why-theres-iphone/

How can I do this effect?

Can you post an example of your code that isn't working? – andorov Oct 31 '15 at 14:52 — andorov, Oct 31 '15 at 14:52
hey @rickywooz - you there bud?! – Fattie Mar 27 '16 at 16:36 — Fattie, Mar 27 '16 at 16:36

score 1 · Answer 1 · edited May 23 '17 at 12:01

It's not THAT easy to do this, unfortunately.

in the first instance, you must learn about gestures in iOS.

UISwipeGestureRecognizer

Your question is of an extremely general nature, and there are 1000s of immediately accessible easy tutorials on using UISwipeGestureRecognizer so you should work through those.

Secondly you have the general concept of "sliding pages around" in iOS.

sliders

It rather depends on precisely what you are trying to achieve, but this for example would be a good first step for you to implement while you are learning about these basic concepts:

sliding screens tutorial on iOS

score 0 · Answer 2 · answered Oct 31 '15 at 15:28

If you are to change UIView background in scroll up/down, you first need "UIScrollView" to be added in the main UIView of the ViewController. Then you should use the UIScrollView delegate method:

func scrollViewDidScroll(scrollView: UIScrollView) {
    if (scrollView == yourScrollView) {
       //change background according to the scrollview content offset.
       if(scrollView.contentOffset.y > some_value && scrollView.contentOffset.y < some value) {
        scrollView.backgroundImage = your_image
        }
    }
}

Before using you should conform the delegate "UIScrollViewDelegate".

How to make iOS App background change with scrolling up/down

2 Answers2