Update NavigationBar with page numbers - iphone

Question

Using pageviewcontroller with page curl transition and wants to update navigation bar with pagenumbers when user turns page.
- (void)viewDidLoad {
[super viewDidLoad];
//modelArray holds the page numbers
modelArray = [[NSMutableArray alloc] init];
for (int index = 1; index <= totalPages; index++) {
[modelArray addObject:[NSString stringWithFormat:#"%i", index]];
}
_navBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 45)];
_navBar.tintColor = [UIColor colorWithRed:243.0/255.0 green:164.0/255.0 blue:0.0/255.0 alpha:1.0];
[self displayPageNumber:1];
thePageViewController = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl navigationOrientation: UIPageViewControllerNavigationOrientationHorizontal options:nil];
thePageViewController.delegate = self;
thePageViewController.dataSource = self;
thePageViewController.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
contentViewController = [[ContentViewController alloc] initWithPDF:PDFDocument];
contentViewController.page = [modelArray objectAtIndex:0];
NSArray *viewControllers = [NSArray arrayWithObject:contentViewController];
[thePageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];
[self addChildViewController:thePageViewController];
[self.view addSubview:thePageViewController.view];
thePageViewController.view.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
[thePageViewController didMoveToParentViewController:self];
_toolbar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 960, self.view.bounds.size.width, 45)];
_toolbar.barStyle = UIBarStyleBlackOpaque;
_toolbar.tintColor = [UIColor colorWithRed:243.0/255.0 green:164.0/255.0 blue:0.0/255.0 alpha:1.0];
[self.view addSubview:_toolbar];
[self.view addSubview:_navBar];
}
- (void) displayPageNumber:(NSUInteger)pageNumber {
UINavigationItem *title = [[UINavigationItem alloc] initWithTitle:[NSString stringWithFormat:
#"Page %i of %i",
pageNumber,
CGPDFDocumentGetNumberOfPages(PDFDocument)]];
[_navBar pushNavigationItem:title animated:NO];
}
Using this code to update navigation bar with pagenumbers when user turns pages
but it is not updating page numbers on navigation bar
- (void) pageViewController:(PageViewController *)pageViewController willTurnToPageAtIndex:(NSUInteger)pageIndex {
[self displayPageNumber:pageIndex + 1];
}
Appreciate help.
Thanks