Content offset stays constant - ios

Question

I've got a UIPageViewController in my app, set up like this:
self.pageViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"MainPageViewController"];
self.pageViewController.dataSource = self;
self.pageViewController.delegate = self;
self.pageViewController.view.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
[self addChildViewController:self.pageViewController];
[self.view addSubview:self.pageViewController.view];
[self.pageViewController didMoveToParentViewController:self];
I've made my UIViewController conform to the UIScrollViewDelegate and added this code to set the scrollView delegate to self:
for (UIView *currentView in self.pageViewController.view.subviews) {
if ([currentView isKindOfClass:[UIScrollView class]]) {
UIScrollView *scrollView = (UIScrollView *)currentView;
scrollView.delegate = self;
break;
}
}
Then I'm trying to use this method to find the current page, though the contentOffset stays the same whenever I scroll the UIPageViewController:
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
CGFloat pageWidth = scrollView.frame.size.width;
NSInteger page = scrollView.contentOffset.x / pageWidth;
NSLog(#"Content offset.x: %.f", scrollView.contentOffset.x);
}
Why is this?

Answer 1

I made it work using a delegate method of the UIPageViewController rather than the scrollView. This is my solution:
-(void)pageViewController:(UIPageViewController *)pageViewController didFinishAnimating:(BOOL)finished previousViewControllers:(NSArray<UIViewController *> *)previousViewControllers transitionCompleted:(BOOL)completed
{
if (completed) {
NSInteger currentIndex = [self.navViewControllers indexOfObject:pageViewController.viewControllers[0]];
}
}