photoview using UIScrollViewController - iphone

Question

I'm trying to make photo album like photo.app in iPhone. I know We have 'PhotoScroller' example from Apple (which I don't think I can copy and paste the code here due to the Non Disclosure Agreement, plus it's bit biggy to play with at the moment). However I found an another example from random search and it seems like based on the PhotoScroller (very simplified tough). The link for the example is ;
http://ykyuen.wordpress.com/2010/05/22/iphone-uiscrollview-with-paging-example/
I applied this code to my project to make photo album (and it scrolls, at least), but I found a problem. The problem is I cannot start from the page I want. The sample code only starts scrolling with Page One. Code itself seems 'really' simple but somehow I just cannot make it start from the page I choose.
Here is main part of the sample code that I found on the Internet. You can of course download the project the link above.
- (void)viewDidLoad {
NSLog(#"ScrollViewWithPagingViewContrller :: viewDidLoad");
[super viewDidLoad];
// view controllers are created lazily
// in the meantime, load the array with placeholders which will be replaced on demand
NSMutableArray *controllers = [[NSMutableArray alloc] init];
for (unsigned i = 0; i < kNumberOfPages; i++) {
[controllers addObject:[NSNull null]];
}
self.viewControllers = controllers;
[controllers release];
// a page is the width of the scroll view
scrollView.pagingEnabled = YES;
scrollView.contentSize = CGSizeMake(scrollView.frame.size.width * kNumberOfPages, scrollView.frame.size.height);
scrollView.showsHorizontalScrollIndicator = NO;
scrollView.showsVerticalScrollIndicator = NO;
scrollView.scrollsToTop = NO;
scrollView.delegate = self;
pageControl.numberOfPages = kNumberOfPages;
pageControl.currentPage = 0;
// pages are created on demand
// load the visible page
// load the page on either side to avoid flashes when the user starts scrolling
[self loadScrollViewWithPage:0];
[self loadScrollViewWithPage:1];}
- (void)loadScrollViewWithPage:(int)page {
NSLog(#"ScrollViewWithPagingViewContrller :: loadScrollViewWithPage");
if (page < 0) return;
if (page >= kNumberOfPages) return;
// replace the placeholder if necessary
MyViewController *controller = [viewControllers objectAtIndex:page];
if ((NSNull *)controller == [NSNull null]) {
controller = [[MyViewController alloc] initWithPageNumber:page];
[viewControllers replaceObjectAtIndex:page withObject:controller];
//
[controller release];
}
// add the controller's view to the scroll view
if (nil == controller.view.superview) {
CGRect frame = scrollView.frame;
frame.origin.x = frame.size.width * page;
frame.origin.y = 0;
controller.view.frame = frame;
[scrollView addSubview:controller.view];
}
}
- (void)scrollViewDidScroll:(UIScrollView *)sender {
NSLog(#"ScrollViewWithPagingViewContrller :: scrollViewDidScroll");
// We don't want a "feedback loop" between the UIPageControl and the scroll delegate in
// which a scroll event generated from the user hitting the page control triggers updates from
// the delegate method. We use a boolean to disable the delegate logic when the page control is used.
if (pageControlUsed) {
// do nothing - the scroll was initiated from the page control, not the user dragging
return;
}
// Switch the indicator when more than 50% of the previous/next page is visible
CGFloat pageWidth = scrollView.frame.size.width;
int page = floor(scrollView.contentOffset.x - pageWidth / 2) / pageWidth;
pageControl.currentPage = page;
// load the visible page and the page on either side of it (to avoid flashes when the user starts scrolling)
[self loadScrollViewWithPage:page - 1];
[self loadScrollViewWithPage:page];
[self loadScrollViewWithPage:page + 1];
// A possible optimization would be to unload the views+controllers which are no longer visible
}
// At the begin of scroll dragging, reset the boolean used when scrolls originate from the UIPageControl
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
NSLog(#"ScrollViewWithPagingViewContrller :: scrollViewWillBeginDragging");
pageControlUsed = NO;
}
// At the end of scroll animation, reset the boolean used when scrolls originate from the UIPageControl
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
NSLog(#"ScrollViewWithPagingViewContrller :: scrollViewDidEndDecelerating");
pageControlUsed = NO;
}
- (IBAction)changePage:(id)sender {
NSLog(#"ScrollViewWithPagingViewContrller :: changePage");
int page = pageControl.currentPage;
// load the visible page and the page on either side of it (to avoid flashes when the user starts scrolling)
[self loadScrollViewWithPage:page - 1];
[self loadScrollViewWithPage:page];
[self loadScrollViewWithPage:page + 1];
// update the scroll view to the appropriate page
CGRect frame = scrollView.frame;
frame.origin.x = frame.size.width * page;
frame.origin.y = 0;
[scrollView scrollRectToVisible:frame animated:YES];
// Set the boolean used when scrolls originate from the UIPageControl. See scrollViewDidScroll: above.
pageControlUsed = YES;
}

Answer 1

I have implemented photo album view where in first view i have shown all the thumbnail images and on clicking each image it gives its full screen view. you also scroo the images.
See this answer.
All the best.

Answer 2

The answer is
scrollView1.contentOffset = CGPointMake( , );
quite simple. spent lot of time.