swift: UIPageViewController action - ios

Question

I have UIPageViewController and this code to flip my pages :
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
let contentVC = viewController as! ContentViewController
if contentVC.itemIndex > 0 {
return getContentViewController(withIndex: contentVC.itemIndex - 1)
}
return nil
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
let contentVC = viewController as! ContentViewController
if contentVC.itemIndex + 1 < images.count {
return getContentViewController(withIndex: contentVC.itemIndex + 1)
}
return nil
}
But I want to flip pages on button press. I should call viewControllerBefore and viewControllerAfter in my button action? Or I should write another code? How to do it?
Update
override func viewDidLoad() {
super.viewDidLoad()
createPageViewController()
setupPageControll()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func createPageViewController() {
let pageController = self.storyboard?.instantiateViewController(withIdentifier: "PageViewController") as! UIPageViewController
pageController.dataSource = self
pageController.delegate = self
if images.count > 0{
let firstController = getContentViewController(withIndex: 0)!
let contentControllers = [firstController]
pageController.setViewControllers(contentControllers, direction: UIPageViewControllerNavigationDirection.forward, animated: true, completion: nil)
}
pageViewController = pageController
self.addChildViewController(pageViewController!)
self.view.insertSubview(pageViewController!.view, at: 0)
pageViewController!.didMove(toParentViewController: self)
}
func presentationCount(for pageViewController: UIPageViewController) -> Int {
return images.count
}
func presentationIndex(for pageViewController: UIPageViewController) -> Int {
return 0
}
func setupPageControll(){
let apperance = UIPageControl.appearance()
apperance.pageIndicatorTintColor = UIColor.gray
apperance.currentPageIndicatorTintColor = UIColor.white
apperance.backgroundColor = UIColor.clear
}
func currentControllerIndex() -> Int{
let pageItemController = self.currentConroller()
if let controller = pageItemController as? ContentViewController {
return controller.itemIndex
}
return -1
}
func currentConroller() -> UIViewController?{
if (self.pageViewController?.viewControllers?.count)! > 0{
return self.pageViewController?.viewControllers![0]
}
return nil
}
func getContentViewController(withIndex index: Int) -> ContentViewController? {
if index < images.count{
let contentVC = self.storyboard?.instantiateViewController(withIdentifier: "ContentViewController") as! ContentViewController
contentVC.itemIndex = index
contentVC.imageName = images[index]
return contentVC
}
return nil
}
}
extension PageViewController: UIPageViewControllerDataSource, UIPageViewControllerDelegate {
func pageViewController(_ pageViewController: UIPageViewController, willTransitionTo pendingViewControllers: [UIViewController]) {
pendingIndex = (pendingViewControllers.first as! ContentViewController).itemIndex
}
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
if completed {
let currentIndex = pendingIndex
if let index = currentIndex {
self.PageControl.currentPage = index
}
}
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
let contentVC = viewController as! ContentViewController
if contentVC.itemIndex > 0 {
return getContentViewController(withIndex: contentVC.itemIndex - 1)
}
return nil
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
let contentVC = viewController as! ContentViewController
if contentVC.itemIndex + 1 < images.count {
return getContentViewController(withIndex: contentVC.itemIndex + 1)
}
return nil
}
New Update
new:
#IBAction func nextAction(_ sender: Any) {
let pageController = self.storyboard?.instantiateViewController(withIdentifier: "PageViewController") as! UIPageViewController
pageController.dataSource = self
pageController.delegate = self
let secondController = getContentViewController(withIndex: 1)!
let contentControllers = [secondController]
pageController.setViewControllers(contentControllers, direction: .forward, animated: true, completion: nil)
pageViewController = pageController
}

Answer 1

You need to use this instance method
setViewControllers(_ viewControllers: [UIViewController]?,
direction: UIPageViewController.NavigationDirection,
animated: Bool,
completion: ((Bool) -> Void)? = nil)
Like this
// self is of type UIPageViewController
self.setViewControllers([vc],direction:.forward,animated:true) { _ in
}

Answer 2

#IBAction func nextPageBtnPressed_TouchupInside(_ sender : UIButton ) {
if let pageViewController = self.parent as? PageViewController {
pageViewController.goToNextPage()
pageViewController.changeCurrentPageIndicator(pageViewController: pageViewController)
}
}
func goToNextPage(animated: Bool = true, completion: ((Bool) -> Void)? = nil) {
if let currentViewController = viewControllers?[0] {
if let nextPage = dataSource?.pageViewController(self, viewControllerAfter: currentViewController) {
setViewControllers([nextPage], direction: .forward, animated: animated, completion: completion)
}
}
func changeCurrentPageIndicator(pageViewController : DTCPageViewController) {
pageViewController.view.clipsToBounds = false
pageViewController.view.sizeToFit()
let pageContentViewController = pageViewController.viewControllers![0]
currentIndex = orderViewController.index(of: pageContentViewController)!
self.pageControl.currentPage = orderViewController.index(of: pageContentViewController)!
}
write goToNextPage() and changeCurrentPageIndicator() ------
In PageViewControllerClass
Or make extension
extension PageViewController