Next Page Button for UIPageViewController iOS - ios

Question

I followed http://www.appcoda.com/uipageviewcontroller-storyboard-tutorial/ for creating a PageViewController.
This tutorial contains :
(code for Restart button)
- (IBAction)restartButton:(id)sender {
PageContentViewController *startingViewController = [self viewControllerAtIndex:0];
NSArray *viewControllers = #[startingViewController];
[self.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionReverse animated:NO completion:nil];
}
When i tried for Next button like this:
- (IBAction)nextPageButton:(id)sender {
PageContentViewController *startingViewController = [self viewControllerAtIndex:+1];
NSArray *viewControllers = #[startingViewController];
[self.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionReverse animated:NO completion:nil];
}
but it fails, how to perform next page action with the UIButton that responds with the PageControl till last page.

Answer 1

That wont work because you are using +1, instead, try this:
//get current index of current page
DataViewController *theCurrentViewController = [self.pageViewController.viewControllers objectAtIndex:0];
NSUInteger retreivedIndex = [self.modelController indexOfViewController:theCurrentViewController];
//check that current page isn't first page
if (retreivedIndex < 5){
//get the page to go to
DataViewController *targetPageViewController = [self.modelController viewControllerAtIndex:(retreivedIndex + 1) storyboard:self.storyboard];
//put it(or them if in landscape view) in an array
NSArray *theViewControllers = nil;
theViewControllers = [NSArray arrayWithObjects:targetPageViewController, nil];
//add page view
[self.pageViewController setViewControllers:theViewControllers direction:UIPageViewControllerNavigationDirectionForward animated:YES completion:NULL];
}

Answer 2

PageNumberToJump=2
-(void)buyAction
{
isFromBuy = YES;
APPChildViewController *initialViewController = [self viewControllerAtIndex:PageNumberToJump];
viewControllers = [NSArray arrayWithObject:initialViewController];
[self.pageController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];
}
-(NSInteger)presentationIndexForPageViewController:(UIPageViewController *)pageViewController
{
if (isFromBuy)
{
isFromBuy = NO;
return PageNumberToJump;
}
return 0;
}