How to Capture click event on Page Control swift - ios

Question

I follow a tutorial on how to create UIPageControl and when I click on the page indicator it do not change the page
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
guard let viewControllerIndex = orderedViewControllers.index(of: viewController) else {
return nil
}
let previousIndex = viewControllerIndex - 1
// User is on the first view controller and swiped left to loop to
// the last view controller.
guard previousIndex >= 0 else {
return orderedViewControllers.last
// Uncommment the line below, remove the line above if you don't want the page control to loop.
// return nil
}
guard orderedViewControllers.count > previousIndex else {
return nil
}
return orderedViewControllers[previousIndex]
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
guard let viewControllerIndex = orderedViewControllers.index(of: viewController) else {
return nil
}
let nextIndex = viewControllerIndex + 1
let orderedViewControllersCount = orderedViewControllers.count
// User is on the last view controller and swiped right to loop to
// the first view controller.
guard orderedViewControllersCount != nextIndex else {
return orderedViewControllers.first
// Uncommment the line below, remove the line above if you don't want the page control to loop.
// return nil
}
guard orderedViewControllersCount > nextIndex else {
return nil
}
return orderedViewControllers[nextIndex]
}
func configurePageControl() {
// The total number of pages that are available is based on how many available colors we have.
pageControl = UIPageControl(frame: CGRect(x: 0,y: UIScreen.main.bounds.maxY - 40,width: UIScreen.main.bounds.width,height: 40))
self.pageControl.numberOfPages = orderedViewControllers.count
self.pageControl.currentPage = 0
self.pageControl.tintColor = UIColor.gray
self.pageControl.pageIndicatorTintColor = UIColor.gray
self.pageControl.currentPageIndicatorTintColor = UIColor.white
self.view.addSubview(pageControl)
}
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
let pageContentViewController = pageViewController.viewControllers![0]
self.pageControl.currentPage = orderedViewControllers.index(of: pageContentViewController)!
}

Answer 1

In configurePageControl() add pageControl.addTarget
func configurePageControl() {
// The total number of pages that are available is based on how many available colors we have.
pageControl = UIPageControl(frame: CGRect(x: 0,y: UIScreen.main.bounds.maxY - 40,width: UIScreen.main.bounds.width,height: 40))
//add target for dots
pageControl.addTarget(self, action: #selector(self.pageControlSelectionAction(_:)), for: .touchUpInside)
self.pageControl.numberOfPages = orderedViewControllers.count
self.pageControl.currentPage = 0
self.pageControl.tintColor = UIColor.gray
self.pageControl.pageIndicatorTintColor = UIColor.gray
self.pageControl.currentPageIndicatorTintColor = UIColor.white
self.view.addSubview(pageControl)
}
Then add the method to change page when a dot is selected.
#objc func pageControlSelectionAction(_ sender: UIPageControl) {
//move page to wanted page
let page: Int? = sender.currentPage
self.pageViewController?.setViewControllers([[orderedViewControllers[page!]]], direction: .forword, animated: true, completion: nil)
}

Answer 2

In my case(Xcode 13), I received previous currentPage.
So use dispatchQueue asyncAfter
#objc func pageControlSelectionAction(_ sender: UIPageControl) {
DispatchQueue.main.asyncAfter(deadline: .now() + 0.1, execute: {
let page: Int? = sender.currentPage
//scroll
}
}
Also I just tested 'DispatchQueue.main.async' was fine.