Pushing ViewController with UIScrollView + UIPageControl onto specific page - iphone

Question

I have a VC with a scrollview and pagecontrol implemented in it. It has three pages, which are all set up correctly and working fine. What I want to be able to do is have the VC load onto different pages depending on what button a user presses.
In the method the button calls I have
ViewController *vc = [[ViewController alloc] init];
vc.pageControl.currentPage = 2;
[self.navigationController pushViewController:vc animated:YES];
When the VC loads, it is loaded onto the correct page (as evidenced by the bubbles at the bottom of the page) but it is displaying the information from page[0]. If I start scrolling, it jumps back to page[0] no matter what I do.
My best guess is that I need to make the VC load to a specific x origin depending on what page I want to display, but I haven't been able to find anything related to this, so I'm quite lost.
Appreciate any help.
EDIT: Here is the code from the VC class. I didn't write this and it is my first time working with PageControl, so I'm trying to learn as I go.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
self.scrollView = [[UIScrollView alloc] init];
self.scrollView.pagingEnabled = TRUE;
self.scrollView.showsVerticalScrollIndicator = NO;
self.scrollView.showsHorizontalScrollIndicator = NO;
self.scrollView.delegate = self;
firstPage = [[UIView alloc] init];
firstPage.tag = 0;
secondPage = [[UIView alloc] init];
secondPage.tag = 1;
thirdPage = [[UIView alloc] init];
thirdPage.tag = 2;
pages = [[NSArray alloc] initWithObjects:firstPage, secondPage, thirdPage, nil];
// Page Control
self.pageControl = [[UIPageControl alloc] init];
self.pageControl.numberOfPages = 3;
self.pageControl.currentPage = 0;
[self.view addSubview:self.scrollView];
[self.view addSubview:self.pageControl];
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// First Page Setup
//
[self setupFirstPage];
// Second Page Setup
//
[self setupSecondPage];
// Third Page Setup
//
[self setupThirdPage];
// Frame everything
//
CGRect screenFrame = [[UIScreen mainScreen] applicationFrame];
CGRect navBarFrame = self.navigationController.navigationBar.frame;
self.scrollView.frame = CGRectMake(0, navBarFrame.size.height, 320, screenFrame.size.height - navBarFrame.size.height);
self.pageControl.frame = CGRectMake(0, screenFrame.size.height - 70, 320, 20);
firstPage.frame = CGRectMake(0, 0, self.scrollView.frame.size.width, self.scrollView.frame.size.height);
secondPage.frame = CGRectMake(320 * secondPage.tag, 0, self.scrollView.frame.size.width, self.scrollView.frame.size.height);
thirdPage.frame = CGRectMake(320 * thirdPage.tag, 0, self.scrollView.frame.size.width, self.scrollView.frame.size.height);
// Add Subviews
//
[self.scrollView addSubview:firstPage];
[self.scrollView addSubview:secondPage];
[self.scrollView addSubview:thirdPage];
self.scrollView.contentSize = CGSizeMake(320 * pages.count, self.scrollView.frame.size.height);
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGFloat pageWidth = self.scrollView.frame.size.width;
int page = floor((self.scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
self.pageControl.currentPage = page;
}

Answer 1

Try adding this function and calling it right after you set the page number:
- (void)pageSelectorChanged
{
CGRect frame = self.scrollView.frame;
frame.origin.x = frame.size.width * self.pageControl.currentPage;
frame.origin.y = 0;
[self.scrollView scrollRectToVisible:frame animated:NO];
}