subview scroll is not working SWIFT

Question

Goal: to make a viewcontroller have multiple pages and can be swapped through a segmented controller, pages content are scrollable vertically

details:

• I made a pagviewcontroller and embedded it as a subview to main viewcontroller

  //add pageviewcontroller as subview to viewcontroller
  if let vc = storyboard?.instantiateViewControllerWithIdentifier("ProfileEditController"){
  
      self.addChildViewController(vc)
      self.view.addSubview(vc.view)
  
      EditTabs = vc as! UIPageViewController
      EditTabs.dataSource = self
      EditTabs.delegate = self
  
      //define First page
      EditTabs.setViewControllers([pagesAtIndexPath(0)!], direction:.Forward, animated: true, completion: nil)
      EditTabs.didMoveToParentViewController(self)
  
      //bring segmented view buttons to front of pageViews
      self.view.bringSubviewToFront(self.topTabs)
  }
  

• I called pageViewController functions, and I am adding pages through restoration Identifiers

• I managed segmented view controller by getting pageindex and setting viewcontroller like this:

  EditTabs.setViewControllers([pagesAtIndexPath(0)!], direction:.Reverse, animated: true, completion: nil)
  

• in story board the sub pages has scroll view inside to hold the content

• I tested subpages scroll view by calling it through segue and its working fine

Case:

• everything work fine Only scroll view of subpages are not working at all

How to solve this issue? your guidelines will be much appreciated

Thanks,

Answer 1

1. I have created a view controller with PageViewController with three View Controllers that have scroll view in it. It works fine.

   import UIKit class ViewController: UIViewController, UIPageViewControllerDataSource {

   var viewControllers : [UIViewController]?
   override func viewDidLoad() {
       super.viewDidLoad()
       CreatePageView()
   }
   
   func CreatePageView() {
   
       SetupViewControllers()
   
       let pageViewController = UIPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal, options: nil)
       pageViewController.dataSource = self
       pageViewController.setViewControllers([(viewControllers?[0])!] , direction: .forward, animated: false, completion: nil)
       pageViewController.view.frame = CGRect(x: 0, y: 0, width: view.frame.size.width, height: view.frame.size.height);
       pageViewController.view.frame = CGRect(x: 0, y: 0, width: view.frame.size.width, height: view.frame.size.height);
       addChildViewController(pageViewController)
       view.addSubview(pageViewController.view)
       pageViewController.didMove(toParentViewController: self)
       pageViewController.view.backgroundColor = UIColor.blue
   }
   
   func SetupViewControllers() {
       let firstVC = UIViewController()
       firstVC.view.tag = 100
       firstVC.view.backgroundColor = UIColor.red
       AddScrollView(bgView: firstVC.view)
       let secondVC = UIViewController()
       secondVC.view.tag = 101
       secondVC.view.backgroundColor = UIColor.brown
       AddScrollView(bgView: secondVC.view)
       let thirdVC = UIViewController()
       thirdVC.view.tag = 102
       thirdVC.view.backgroundColor = UIColor.purple
       AddScrollView(bgView: thirdVC.view)
   
       viewControllers = [firstVC,secondVC,thirdVC]
   
   }
   
   func AddScrollView(bgView: UIView) {
       let scrollView = UIScrollView()
       scrollView.frame = CGRect.init(x: 10, y: 10, width: bgView.frame.width-20, height: bgView.frame.height-20)
       scrollView.backgroundColor = UIColor.init(red: 0.34, green: 0.45, blue: 0.35, alpha: 0.9)
       bgView.addSubview(scrollView)
       scrollView.contentSize = CGSize.init(width: scrollView.frame.size.width, height: scrollView.frame.size.height+200)
   }
   
   
   func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
       if viewController.view.tag == 101 {
           return viewControllers?[0]
       }
       else if viewController.view.tag == 102{
           return viewControllers?[1]
       }
       else{
           return viewControllers?[2]
       }
   }
   
   public func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
       if viewController.view.tag == 101 {
           return viewControllers?[0]
       }
       else if viewController.view.tag == 102{
           return viewControllers?[1]
       }
       else{
           return viewControllers?[2]
       }
   }
   
   func presentationCount(for pageViewController: UIPageViewController) -> Int {
       return (viewControllers?.count)!
   }
   
   func presentationIndex(for pageViewController: UIPageViewController) -> Int {
       return 0
   }
   

   }

Answer 2

Similar issues are raised fairly often on Stack. For my own issue in very similar circumstances, I too was able to use the scrollview without issue in it's own view, but when used as a subview in another subview, I needed to set the scrollview dimensions programatically.

Swift 2

scrollView.setFrame(CGRectMake(0, 0, DEVICE_WIDTH, DEVICE_HEIGHT))

or

Swift 3

scrollView.setFrame(CGRect(x: 0, y: 0, width: DEVICE_WIDTH, height: DEVICE_HEIGHT))

A further (and often viewed as a better) suggestion, automatically set the size based on contents.

var contentRect = CGRectZero
for view in self.scrollView.subviews {
    contentRect = CGRectUnion(contentRect, view.frame)
}
self.scrollView.contentSize = contentRect.size 

Hope this helps.