Swift UIScrollViewDelegate not triggers scrollViewDidScroll event

Question

I have two UIScrollViews in my UIViewController both of them have different properties such as pagingEnabled, contentSize & contentInset also i need them to behave separately when scrolling so i create two separate custom classes like below.

class NavigationScrollView: UIScrollView{

}

class ContentScrollView: UIScrollView{

}

also delegates

extension NavigationScrollView: UIScrollViewDelegate{
    // this method not triggers
    func scrollViewDidScroll(scrollView: UIScrollView) {

    }
}
extension ContentScrollView: UIScrollViewDelegate{
    // this method not triggers
    func scrollViewDidScroll(scrollView: UIScrollView) {

    }    
}

In main viewController viewDidLoad() i do

navigationScroller = NavigationScrollView(frame: CGRectMake(0.0, 0.0, frameWidth, 40.0))
contentScroller = ContentScrollView(frame: CGRectMake(0.0, 0.0, frameWidth, frameHeight))

Answer 1

how about you assign the delegate this way?

    class NavigationScrollView: UIScrollView{
        override func didMoveToSuperview() {
            super.didMoveToSuperview()
            self.delegate = self
        }
    }

    class ContentScrollView: UIScrollView{
        override func didMoveToSuperview() {
            super.didMoveToSuperview()
            self.delegate = self
        }
    }