UIPageViewController set limit page - ios

Question

I'm starting study swift, and use UIPageViewController to slide 3 page. I use class:
import Foundation
import UIKit
class MyPageViewController: UIPageViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate {
var pages = [UIViewController]()
var pageIndicator : UIPageControl!
override func viewDidLoad() {
super.viewDidLoad()
self.delegate = self
self.dataSource = self
let page1: UIViewController! = storyboard?.instantiateViewControllerWithIdentifier("page1")
let page2: UIViewController! = storyboard?.instantiateViewControllerWithIdentifier("page2")
let page3: UIViewController! = storyboard?.instantiateViewControllerWithIdentifier("page3")
pages.append(page1)
pages.append(page2)
pages.append(page3)
setViewControllers([page1], direction: UIPageViewControllerNavigationDirection.Forward, animated: false, completion: nil)
}
func viewControllerAtIndex(index: Int) -> UINavigationController! {
return nil
}
func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {
let currentIndex = pages.indexOf(viewController)!
pageIndicator.currentPage = currentIndex
let previousIndex = abs((currentIndex - 1) % pages.count)
return pages[previousIndex]
}
func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {
let currentIndex = pages.indexOf(viewController)!
pageIndicator.currentPage = currentIndex
let nextIndex = abs((currentIndex + 1) % pages.count)
return pages[nextIndex]
}
func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int {
return pages.count
}
func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int {
return 0
}
}
But sliding didn't stops on the third page, and begins again with first page.
How limit slide page forward and backward?

Answer 1

I think your index calculation is wrong in the following line.
`
let nextIndex = abs((currentIndex + 1) % pages.count)
return pages[nextIndex]`
for the last view controller currentIndex=2 ,then nextIndex=(2+1)%3=0.
So you are returning the view controller at index 0 again.
add the following line to your method `
if(currentIndex == (pages.count-1))
{
return nil;
}
`Note:this is according to objective c.

Answer 2

As UIBittu already pointed out: your calculation needs a fix.
A possible (probably more readable) solution may look like this:
func indexOfViewController(viewController: UIViewController) -> Int {
guard let index = pages.indexOf(viewController) else {
return NSNotFound
}
return index
}
func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {
var index = indexOfViewController(viewController)
if (index == 0) || (index == NSNotFound) {
return nil
}
index--
return pages[index]
}
func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {
var index = indexOfViewController(viewController)
if (index == NSNotFound) || (index+1 == pages.count) {
return nil
}
index++
return pages[index]
}

Answer 3

This is different solution.
You don't need to have a full set of complex code to execute what you need.
Create a ScrollView. Set its content size width as the multiple of number of pages.
Try this code. this may help You
override func viewDidLoad() {
super.viewDidLoad()
let screensize = UIScreen.mainScreen().bounds
pagescroll.frame = CGRectMake(0, 0,screensize.width, screensize.height)
pagescroll.contentSize = CGSize(width: screensize.width*3, height: screensize.height)
pagescroll.pagingEnabled = true
page1.frame = CGRectMake(0, 0, screensize.width, screensize.height)
page2.frame = CGRectMake(screensize.width, 0, screensize.width, screensize.height)
page3.frame = CGRectMake(screensize.width*2, 0, screensize.width, screensize.height)
pagescroll.addSubview(page1)
pagescroll.addSubview(page2)
pagescroll.addSubview(page2)
self.view.addSubview(pagescroll)
// Do any additional setup after loading the view.
}
var pagescroll = UIScrollView()
var page1 = UIView()
var page2 = UIView()
var page3 = UIView()
You can also add a pagecontroller: UIPageControl according to your requirement