The UIPageViewControllerDataSource is not being called from ViewDidLoad, hence only the first page is displayed and swipe doesn't do anything.
I have followed this tutorial:
https://spin.atomicobject.com/2015/12/23/swift-uipageviewcontroller-tutorial/
The answers in questions similar to this do not work. I have viewed 5 similar questions but none of them work for me.
class SetupViewController: UIPageViewController {
private(set) lazy var pages : [UIViewController] = {
return [self.newPage(1), self.newPage(2), self.newPage(3), self.newPage(4)]
}()
private func newPage(_ page: Int) -> UIViewController {
return UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "Page\(page)")
}
override func viewDidLoad() {
super.viewDidLoad()
dataSource = self
if let firstPage = pages.first {
print(#function, "if let firstPage", firstPage, pages) //viewDidLoad() if let firstPage page1name [page1, page2, page3, page4]
setViewControllers([firstPage], direction: .forward, animated: true, completion: nil)
}
}
}
extension SetupViewController: UIPageViewControllerDataSource {
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
print(#function) //It doesn't print
guard let pageIndex = pages.firstIndex(of: viewController) else { return nil }
let nextIndex = pageIndex + 1
let pageCount = pages.count
guard nextIndex != pageCount else { return nil }
guard pageCount > nextIndex else { return nil }
return pages[nextIndex]
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
print(#function) //It doesn't print
guard let pageIndex = pages.firstIndex(of: viewController) else { return nil }
let previousIndex = pageIndex - 1
guard previousIndex >= 0 else { return nil }
guard pages.count > previousIndex else { return nil }
return pages[previousIndex]
}
}
Storyboard IDs are: Page1, Page2, Page3 & Page4
What am I doing wrong?
May be you have a configuration problem i have created a demo here
https://github.com/ShKhan9/PagerShow
let wind = (UIApplication.shared.delegate as! AppDelegate).window!
wind.rootViewController = SetupViewController()
Related
I am working on a project with 3 views that are accessed by swiping.
The following code implements the PageViewController I am using to handle the swiping motion:
import UIKit
class PageViewController: UIPageViewController, UIPageViewControllerDelegate, UIPageViewControllerDataSource {
lazy var orderedViewControllers : [UIViewController] = {
return [self.newVC(viewController : "ClimaVC"),
self.newVC(viewController : "WeatherVC"),
self.newVC(viewController : "ClosetVC")]
}()
var myViewControllers = [UIViewController]()
var currentIndex : Int = 0
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
self.dataSource = self
setViewControllers([orderedViewControllers[1]],
direction: .forward, animated: true, completion: nil)
self.delegate = self
}
func newVC(viewController : String) -> UIViewController {
return UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: viewController)
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
guard let viewControllerIndex = orderedViewControllers.index(of: viewController) else {
return nil
}
let previousIndex = viewControllerIndex - 1;
guard previousIndex >= 0 else {
// return orderedViewControllers.last
//Return nil to avoid swiping forever.
return nil
}
guard orderedViewControllers.count > previousIndex else {
return nil
}
currentIndex = previousIndex
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;
guard orderedViewControllers.count != nextIndex else {
//return orderedViewControllers.first
//Return nil to avoid swiping forever.
return nil
}
guard orderedViewControllers.count > nextIndex else {
return nil
}
return orderedViewControllers[nextIndex]
}
}
The main View Controller is WeatherVC. In this view, time data is retrieved and stored in an integer variable named timeOfDay.
Depending on the value of timeOfDay, the background displayed will differ. While I was able to use this variable in WeatherVC, I need to pass this variable timeOfDay to the two other view controllers ClimaVC and ClosetVC.
I tried setting up a delegate protocol but failed, explored using the different functions provided by UIPageViewControllerDelegate and it did not get me anywhere.
I would really appreciate some help on this,
Thank you very much!
It's not complicated, just assign the values at the pageviewcontroller datasources.
import UIKit
class ClimaViewController: UIViewController{
var timeOfDayClima: Int = 0
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
print (timeOfDayClima)
}
}
class WeatherViewController: UIViewController{
var timeOfDayClima: Int = 0
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
timeOfDayClima += 1
}
}
class ClosetViewController: UIViewController{
var timeOfDayClima: Int = 0
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
print (timeOfDayClima)
}
}
class PageViewController: UIPageViewController, UIPageViewControllerDelegate, UIPageViewControllerDataSource {
lazy var orderedViewControllers : [UIViewController] = {
return [self.newVC(viewController : "ClimaVC"),
self.newVC(viewController : "WeatherVC"),
self.newVC(viewController : "ClosetVC")]
}()
var myViewControllers = [UIViewController]()
var currentIndex : Int = 0
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
self.dataSource = self
setViewControllers([orderedViewControllers[1]],
direction: .forward, animated: true, completion: nil)
self.delegate = self
}
func newVC(viewController : String) -> UIViewController {
return UIStoryboard(name: "Second", bundle: nil).instantiateViewController(withIdentifier: viewController)
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
//Guard = some kind of if statement.
guard let viewControllerIndex = orderedViewControllers.index(of: viewController) else {
return nil
}
let previousIndex = viewControllerIndex - 1;
guard previousIndex >= 0 else {
// return orderedViewControllers.last
//Return nil to avoid swiping forever.
return nil
}
guard orderedViewControllers.count > previousIndex else {
return nil
}
currentIndex = previousIndex
if(currentIndex == 0) {
(orderedViewControllers.first as! ClimaViewController).timeOfDayClima = (orderedViewControllers[1] as! WeatherViewController).timeOfDayClima
}
return orderedViewControllers[previousIndex]
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
//Guard = some kind of if statement.
guard let viewControllerIndex = orderedViewControllers.index(of: viewController)
else {
return nil
}
let nextIndex = viewControllerIndex + 1;
guard orderedViewControllers.count != nextIndex else {
//return orderedViewControllers.first
//Return nil to avoid swiping forever.
return nil
}
guard orderedViewControllers.count > nextIndex else {
return nil
}
currentIndex = nextIndex
if(currentIndex == orderedViewControllers.count - 1) {
(orderedViewControllers.last as! ClosetViewController).timeOfDayClima = (orderedViewControllers[1] as! WeatherViewController).timeOfDayClima
}
if(nextIndex == 0) {
let secondVC = self.storyboard?.instantiateViewController(withIdentifier: "ClimaVC") as! ClimaViewController
secondVC.timeOfDayClima = 1
}
return orderedViewControllers[nextIndex]
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
Maybe you should try explaining what has failed in setting up your delegate protocol as well because it seems like it is likely the solution you are looking for. I'm writing a protocol here for reference but you have to change it according to your needs.
protocol WeatherVCDelegate {
func changedTime(timeOfDay: Int)
}
Here comes the tricky part. When you declare a delegate in WeatherVC, you need to use the delegate to call the function to relay the timeOfDay to other weatherVC. How this works is that anything that conforms to the delegate protocol will be triggered to use the function.
class WeatherVC {
weak var delegate: WeatherVCDelegate?
func functionName() {
delegate?.changedTime(timeOfDay: value)
}
Now, when you initialize weatherVC in your PageViewController, you need PageViewController to conform to weatherVC delegate.
In PageViewController...
weatherVC.delegate = self
extension PageViewController: WeatherVCDelegate {
...
}
Here is more read up about delegates if my answer is not clear enough
https://medium.com/#jamesrochabrun/implementing-delegates-in-swift-step-by-step-d3211cbac3ef
This is my code for pageView . It does not scroll. I am using swift2 because of unavailability of swift4 in my setup. Can anyone help me I am Fresher!
import UIKit
class TutorialPageViewController:UIPageViewController,UIPageViewControllerDataSource,UIPageViewControllerDelegate
{
//Storyboard class and id -
//ViewController1,ViewController2,ViewController3
private(set) lazy var orderedViewControllers: [UIViewController] = {
return [self.newColoredViewController("ViewController1"),
self.newColoredViewController("ViewController2"),
self.newColoredViewController("ViewController3")]
}()
private func newColoredViewController(name: String) -> UIViewController {
return UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("name")
}
//code of pageview
override func viewDidLoad() {
super.viewDidLoad()
self.dataSource = self
self.delegate = self
if let ViewController1 = orderedViewControllers.first {
setViewControllers([ViewController1],
direction: .Forward,
animated: true,
completion: nil)
}
}
You need to implement UIPageViewControllerDataSource too :
extension Yourcontroller: UIPageViewControllerDataSource{
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]
}
}
I have a page view controller that allows me to scroll through the various signup pages and enter the necessary information. The problem is it just scrolls in a circle. How do I make it so that the PlayerInfo page is the last page I can scroll to?
lazy var SignupArray : [UIViewController] = {
return [self.VCInstance(name: "ParkSelect"),
self.VCInstance(name: "SportSelect"),
self.VCInstance(name: "PlayerInfo")]
}()
private func VCInstance(name: String) -> UIViewController {
return UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: name)
}
override func viewDidLoad() {
super.viewDidLoad()
self.dataSource = self
self.delegate = self
if let firstVC = SignupArray.first {
setViewControllers([firstVC], direction: .forward, animated: true, completion: nil)
}
}
public func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController?{
guard let viewControllerIndex = SignupArray.index(of: viewController) else {
return nil
}
let previousIndex = viewControllerIndex - 1
guard previousIndex >= 0 else {
return SignupArray.last
}
guard SignupArray.count > previousIndex else {
return nil
}
return SignupArray[previousIndex]
}
public func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController?{
guard let viewControllerIndex = SignupArray.index(of: viewController) else {
return nil
}
let nextIndex = viewControllerIndex + 1
guard nextIndex < SignupArray.count else {
return SignupArray.first
}
guard SignupArray.count > nextIndex else {
return nil
}
return SignupArray[nextIndex]
}
public func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController?{
guard let viewControllerIndex = SignupArray.index(of: viewController) else {
return nil
}
let previousIndex = viewControllerIndex - 1
guard previousIndex >= 0 else {
return nil
}
return SignupArray[previousIndex]
}
public func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController?{
guard let viewControllerIndex = SignupArray.index(of: viewController) else {
return nil
}
let nextIndex = viewControllerIndex + 1
guard SignupArray.count > nextIndex else {
return nil
}
return SignupArray[nextIndex]
}
The reason it is endless because
when previousIndex becomes zero you pass the last VC in array
guard previousIndex >= 0 else {
return SignupArray.last
}
when nextIndex is equal to count of signUp array u pass the first VC in array.
guard nextIndex < SignupArray.count else {
return SignupArray.first
}
Remove these two code and ur PageViewer will stop
Return nil instead of wrapping around. For example:
public func pageViewController(_ pvc: UIPageViewController, viewControllerAfter vc: UIViewController) -> UIViewController?{
guard
let i = SignupArray.index(of: vc),
i < SignupArray.count - 1
else {
return nil
}
return SignupArray[i + 1]
}
or, even more concisely:
public func pageViewController(_ pvc: UIPageViewController, viewControllerAfter vc: UIViewController) -> UIViewController?{
let i = 1 + (SignupArray.index(of: vc) ?? SignupArray.count)
return i < SignupArray.count ? SignupArray[i] : nil
}
I have a page control in my project and I want to do two things :
1. I want to hide indicator dots in the last page
2. I want to lock the last page in the (page VC(my class)) that I can't come back to the first page
here is my code
class pageVC : UIPageViewController , UIPageViewControllerDataSource , UIPageViewControllerDelegate {
lazy var VCArr : [UIViewController] = {
return [self.VCInstance(name : "FirtsVC"),
self.VCInstance(name : "SecondVC"),
self.VCInstance(name :"ThirdVC"),
self.VCInstance(name :"FourthVC"),
self.VCInstance(name :"FivethVC")]
}()
private func VCInstance(name : String) -> UIViewController {
return UIStoryboard(name : "Main" , bundle : nil).instantiateViewController(withIdentifier: name)
}
override func viewDidLoad() {
super.viewDidLoad()
self.dataSource = self
self.delegate = self
if VCArr.last != nil {
print("first Page Reached!")
}
if let firstVC = VCArr.first {
setViewControllers([firstVC] , direction: .forward , animated: true, completion: nil)
}
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
let pageVC = UIPageControl()
for view in self.view.subviews {
if view is UIScrollView {
view.frame = UIScreen.main.bounds
}else if view is UIPageControl{
view.backgroundColor = UIColor.clear
pageVC.numberOfPages = 5
pageVC.center = self.view.center
pageVC.layer.position.y = self.view.frame.height - 180 ;
}
}
}
public func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController?{
guard let viewControllerIndex = VCArr.index(of: viewController) else {
return nil
}
let previousIndex = viewControllerIndex-1
guard previousIndex >= 0 else {
return VCArr.last
}
guard VCArr.count > previousIndex else {
return nil
}
return VCArr[previousIndex]
}
public func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController?{
guard let viewControllerIndex = VCArr.index(of: viewController) else {
return nil
}
let nextIndex = viewControllerIndex+1
guard nextIndex < VCArr.count
else {
return VCArr.first
}
guard VCArr.count > nextIndex else {
return nil
}
return VCArr[nextIndex]
}
public func presentationCount(for pageViewController: UIPageViewController) -> Int{
return VCArr.count
}
public func presentationIndex(for pageViewController: UIPageViewController) -> Int{
guard let firstViewController = viewControllers?.first , let firstViewControllerIndex = VCArr.index(of: firstViewController) else {
return 0
}
return firstViewControllerIndex
}
public func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
if (VCArr.last!.isViewLoaded)
{
print("It is Done!!!")
}
}
Change this, which is making the page view to return to the first one when it is in the last one:
let nextIndex = viewControllerIndex+1
guard nextIndex < VCArr.count
else {
return nil //was VCArr.first
}
And to make it hidden, first move the let pageVC = UIPageControl() below the class pageVC : UIPageViewController , UIPageViewControllerDataSource , UIPageViewControllerDelegate { to make it public within the class. Then add:
if nextIndex == VCArr.count{
pageVC.isHidden = true
}
I have a pageViewController with 3 viewControllers which is embedded in a view of a viewcontroller.
i am setting the view controllers programatically:
lazy var vcArr: [UIViewController] = {
return [self.vcInstance(name: "vc1"),
self.vcInstance(name: "vc2"),
self.vcInstance(name: "vc3"),
]
}()
i am programatically setting the number of pages to 4
let pageController = UIPageControl.appearance()
pageController.numberOfPages = 4
what i want to happen is that if the user tries to swipe right from the 3rd page it will segue to a signup viewController.
I'm currently trying to achieve this in the viewcontroller after function testing for it the next item is greater than or equal to the total count.
public func pageViewController(_ pageViewController: UIPageViewController,
viewControllerAfter viewController: UIViewController) -> UIViewController? {
guard let viewControllerIndex = vcArr.index(of: viewController) else {
return nil
}
let nextIndex = viewControllerIndex + 1
if nextIndex >= vcArr.count {
infoClick()
return nil
} else {
guard nextIndex < vcArr.count else {
return self.vcArr.last
}
guard self.vcArr.count > nextIndex else {
return nil
}
return self.vcArr[nextIndex]
}
}
with this test the way it is sometimes it stops on page 3 and then when swiped right it will segue off with my function infoClick(). however somethings it goes right off when it hits the 3rd page as you would think because its > or = the number of pages which is 3.
when i change this to just > it doesn't display anything on the third page.
I've searched heaps for a way around this but to no avail. does anyone have any ideas how to achieve this?
attaching entire class below:
import UIKit
import Parse
class pageViewController: UIPageViewController, UIPageViewControllerDelegate, UIPageViewControllerDataSource {
#IBOutlet var createAccountBarButton: UIBarButtonItem!
lazy var vcArr: [UIViewController] = {
return [self.vcInstance(name: "vc1"),
self.vcInstance(name: "vc2"),
self.vcInstance(name: "vc3"),
]
}()
override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
return .portrait
}
//---------------------------------------------- autoLogin
/// temporary location, needs to be launched during the loading screen
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(true)
// if (PFUser.current() != nil) {
// let vc = self.storyboard!.instantiateViewController(withIdentifier: "PackViewController")
// self.present(vc, animated: true, completion: nil)
// if (PFUser.current() != nil) {
// let tbc = self.storyboard!.instantiateViewController(withIdentifier: "MyTabController") as! UITabBarController
// tbc.selectedIndex = 1
// self.present(tbc, animated: true, completion: nil)
// }
}
//---------------------------------------------- set the viewcontrollwe instance
private func vcInstance(name: String) -> UIViewController {
return UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: name)
}
//---------------------------------------------- set the direction and first page of the page controller
override func viewDidLoad() {
super.viewDidLoad()
self.tabBarController?.tabBar.isHidden = true
let pageController = UIPageControl.appearance()
pageController.pageIndicatorTintColor = UIColor.lightGray
pageController.currentPageIndicatorTintColor = GeneralFunctions.UIColorFromHEX(hexValue: 0xbb0d2a)
pageController.backgroundColor = UIColor.clear
pageController.bounds = CGRect(x: 0, y: 0, width: 0, height: 0)
pageController.numberOfPages = 4
//GeneralFunctions.commonButtonSettings(buttonName: signUpButton, hexValue: 0x0c1537)
self.dataSource = self
self.dataSource = self
if let firstVC = vcArr.first {
setViewControllers([firstVC], direction: .forward, animated: true, completion: nil)
}
}
//---------------------------------------------- page view controller before settings
public func pageViewController(_ pageViewController: UIPageViewController,
viewControllerBefore viewController: UIViewController) -> UIViewController? {
guard let viewControllerIndex = vcArr.index(of: viewController) else {
return nil
}
let previousIndex = viewControllerIndex - 1
if previousIndex < 0 {
return nil
} else {
guard previousIndex >= 0 else {
return self.vcArr.last
}
guard self.vcArr.count > previousIndex else {
return nil
}
return self.vcArr[previousIndex]
}
}
//---------------------------------------------- page view controller after settings
public func pageViewController(_ pageViewController: UIPageViewController,
viewControllerAfter viewController: UIViewController) -> UIViewController? {
guard let viewControllerIndex = vcArr.index(of: viewController) else {
return nil
}
let nextIndex = viewControllerIndex + 1
if nextIndex >= vcArr.count {
infoClick()
return nil
} else {
guard nextIndex < vcArr.count else {
return self.vcArr.last
}
guard self.vcArr.count > nextIndex else {
return nil
}
return self.vcArr[nextIndex]
}
}
//---------------------------------------------- presentation count
public func presentationCount(for pageViewController: UIPageViewController) -> Int {
return self.vcArr.count
}
//---------------------------------------------- presentation index
public func presentationIndex(for pageViewController: UIPageViewController) -> Int {
guard let firstViewController = viewControllers?.first,
let firstViewControllerIndex = vcArr.index(of: firstViewController) else {
return 0
}
return firstViewControllerIndex
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
//---------------------------------------------- launch the new view controller - still launching before swipped to 4th window sometimes
// not sure if this is the best way to do this need to look at this a bit more
func infoClick() {
let storyboard: UIStoryboard = UIStoryboard (name: "Main", bundle: nil)
let vc: SignupViewController = storyboard.instantiateViewController(withIdentifier: "SignupViewController") as! SignupViewController
let currentController = getCurrentViewController()
currentController?.present(vc, animated: false, completion: nil)
}
func getCurrentViewController() -> UIViewController? {
if let rootController = UIApplication.shared.keyWindow?.rootViewController {
var currentController: UIViewController! = rootController
while( currentController.presentedViewController != nil ) {
currentController = currentController.presentedViewController
}
return currentController
}
return nil
}
}