UIPageViewController is not working correctly (page indicators are out of sync with the current page)

Question

UIPageViewController is not working correctly (page indicators are out of sync with the current page)

In my application, I have a UIPageViewController. Sometimes the following two functions are called incorrectly.

 pageViewController:ViewControllerBeforeViewController
 pageViewController:ViewControllerAfterViewController

I have a page indicator that is triggered from these two functions. Sometimes it will not sync with the current page. Here is the code I am using in my application.

-(void)setPageView
{
    self.pageViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"PageViewController"];
    self.pageViewController.dataSource = self;
    NSArray *viewControllers ;
    currentTab = 0;

    if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)


      {

            ContentCardListViewController *startingViewController = (ContentCardListViewController*)[self viewControllerAtIndex:0];
           viewControllers = @[startingViewController];

        }
        else
        {
        IpadContentCardCollectionViewController *startingViewController = (IpadContentCardCollectionViewController*)[self viewControllerAtIndex:0];
            viewControllers = @[startingViewController];

        }
        [self setTabTextColor:0];

           [self.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];

        // Change the size of page view controller
        //self.pageViewController.view.frame = _pagerView.frame;
        self.pageViewController.view.frame = CGRectMake(0, 0, _pagerView.frame.size.width, _pagerView.frame.size.height);
        [self addChildViewController:_pageViewController];
        [self.pagerView addSubview:_pageViewController.view];

        [self.pageViewController didMoveToParentViewController:self];
    }

 #pragma mark - PageViewController
- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
{
    NSUInteger index;
    if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
    {

    index = ((ContentCardListViewController*) viewController).pageIndex;
    }
    else
    {
        index=((IpadContentCardCollectionViewController*) viewController).pageIndex;

    }
    [self setTabTextColor:(int)index];

    if (index == 0) {
        return nil;
    }
    currentTab = (int)index;
//    if (index<4) {
//        [_horizontalTabScrollView setContentOffset:CGPointMake(self.horizontalTabScrollView.contentOffset.x-50,self.horizontalTabScrollView.contentOffset.y) animated:YES];
//        
//    }
    index--;
    NSLog(@"Befor nw=%d",(int)index);
    return [self viewControllerAtIndex:index];
}

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
{
    NSUInteger index;
    if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
    {

   index = ((ContentCardListViewController*) viewController).pageIndex;
    }
    else
    {
    index = ((IpadContentCardCollectionViewController*) viewController).pageIndex;

    }
    currentTab = (int)index;
    [self setTabTextColor:(int)index];

    if (index == NSNotFound) {
        return nil;
    }

    index++;
    if (index ==6) {
        return nil;
    }
//    if (index>3) {
//        [_horizontalTabScrollView setContentOffset:CGPointMake(self.horizontalTabScrollView.contentOffset.x+50,self.horizontalTabScrollView.contentOffset.y) animated:YES];
//
//    }

    NSLog(@"After nw=%d",(int)index);
    return [self viewControllerAtIndex:index];
}
- (UIViewController *)viewControllerAtIndex:(NSUInteger)index
{
//    if (index >6) {
//        return nil;
//    }
    ContentCardListViewController *contentCardListViewController ;
    IpadContentCardCollectionViewController *contentCardIpad ;

    // Create a new view controller and pass suitable data.
    if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
    {

    contentCardListViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"ContentCardViewController"];

    contentCardListViewController.pageIndex = index;
        return contentCardListViewController;

    }
    contentCardIpad = [self.storyboard instantiateViewControllerWithIdentifier:@"ContentCardViewControllerIpad"];

    contentCardIpad.pageIndex = index;
    return contentCardIpad;
}