playing a sound file in a pageControler with Xcode and Swift - ios

Question

I would like to play a sound file when a new page comes on the screen.
So far I did that to have the pageControler working with an array of images.
Can someone tell me where I have to put my code in order to play an array of sound? So that the sound1 will be played when the image1 comes on the screen.
import UIKit
class ViewController: UIViewController, UIScrollViewDelegate {
#IBOutlet weak var pageControl: UIPageControl!
#IBOutlet weak var scrollView: UIScrollView!
var images: [String] = ["1", "2", "3", "4", "5"]
var frame = CGRect(x:0,y:0, width:0, height:0)
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
pageControl.numberOfPages = images.count
for index in 0..<images.count {
frame.origin.x = scrollView.frame.size.width * CGFloat(index)
frame.size = scrollView.frame.size
let imgView = UIImageView(frame: frame)
imgView.image = UIImage(named: images[index])
self.scrollView.addSubview(imgView)
}
scrollView.contentSize = CGSize(width:(scrollView.frame.size.width * CGFloat(images.count)), height: scrollView.frame.size.height)
scrollView.delegate = self
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
var pageNumber = scrollView.contentOffset.x / scrollView.frame.size.width
pageControl.currentPage = Int(pageNumber)
}
}

Answer 1

I don't see a direct way to get called when the selected page changes. You could add code in your page view controller's setViewControllers(_:direction:animated:completion:) method that figures out which page is active and plays the appropriate sound.
If you use a page control you could probably also subclass UIPageControl and use a didSet on the currentPage property to figure out which sound to play.
Edit:
Just add a new file, make it a Cocoa touch class, and make it a subclass of UIPageControl. Name it CustomPageControl. Then your implementation can be as simple as this:
import UIKit
class CustomPageControl: UIPageControl {
override var currentPage: Int {
didSet {
//Your code to play sounds based on selected index could go
//here, or broadcast a notification that your view controller
//would listen for
print("New page index = \(currentPage)")
}
}
}
Then just select the page control on your UIPageViewController, select the "Identity Inspector", and change the class of the page control to your custom CustomPageControl class. Once you've done that, whenever your page index changes, the didSet method above will be called.