Images not loading in UIScrollView for gallery app

galleryviewcontroller.h

#import


@interface GalleryViewController : UIViewController {
UIScrollView *scrollView;
UIPageControl *pageControl;
    NSMutableArray *viewControllers;
    NSArray *contentList;

    // To be used when scrolls originate from the UIPageControl
    BOOL pageControlUsed;
}

@property (nonatomic, retain) IBOutlet UIScrollView *scrollView;
@property (nonatomic, retain) NSMutableArray *viewControllers;
@property (nonatomic, retain) NSArray *contentList;

- (IBAction)changePage:(id)sender;

-(IBAction)back:(id)sender;

@end

galleryviewcontroller.m

#import \"GalleryViewController.h\"
#import \"MyViewController.h\"






static NSString *ImageKey = @\"imageKey\";

static NSUInteger kNumberOfPages = 29;




@interface GalleryViewController (PrivateMethods)

- (void)loadScrollViewWithPage:(int)page;
- (void)scrollViewDidScroll:(UIScrollView *)sender;

@end

@implementation GalleryViewController

-(IBAction)back:(id)sender{

[self.view removeFromSuperview];

}

@synthesize scrollView, viewControllers, contentList;

/*
 // The designated initializer. Override to perform setup that is required before the view is loaded.
 - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
 if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
 // Custom initialization
 }
 return self;
 }
 */

/*
 // Implement loadView to create a view hierarchy programmatically, without using a nib.
 - (void)loadView {
 }
 */


/*
 // Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
 */
- (void)viewDidLoad {




NSString *path = [[NSBundle mainBundle] pathForResource:@\"Gallery\" ofType:@\"plist\"];
        self.contentList = [NSArray arrayWithContentsOfFile:path];


// 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;

    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];


    [super viewDidLoad];


}

- (void)loadScrollViewWithPage:(int)page {
    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];


        NSDictionary *numberItem = [self.contentList objectAtIndex:page];
        controller.numberImage.image = [UIImage imageNamed:[numberItem valueForKey:ImageKey]];
    }


}

- (void)scrollViewDidScroll:(UIScrollView *)sender {
    // 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) + 1;
    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 {
    pageControlUsed = NO;
}

// At the end of scroll animation, reset the boolean used when scrolls originate from the UIPageControl
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
    pageControlUsed = NO;
}

- (IBAction)changePage:(id)sender {
    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;
}





/*
 // Override to allow orientations other than the default portrait orientation.
 - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
 // Return YES for supported orientations
 return (interfaceOrientation == UIInterfaceOrientationPortrait);
 }
 */

- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

// Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}


- (void)dealloc {
    [viewControllers release];
    [scrollView release];
    [pageControl release];
    [contentList release];

    [super dealloc];
}

@end

myviewcontroller.h
#import


@interface MyViewController : UIViewController {
UILabel *pageNumberLabel;
    int pageNumber;
        UIImageView *numberImage;
}

@property (nonatomic, retain) IBOutlet UILabel *pageNumberLabel;
@property (nonatomic, retain) IBOutlet UIImageView *numberImage;

- (id)initWithPageNumber:(int)page;

@end

myviewcontroller.m

#import \"MyViewController.h\"


@implementation MyViewController

@synthesize pageNumberLabel, numberImage;



// Load the view nib and initialize the pageNumber ivar.
- (id)initWithPageNumber:(int)page {
    if (self = [super initWithNibName:@\"MyViewController\" bundle:nil]) {
        pageNumber = page;
    }
    return self;
}



// Set the label and background color when the view has finished loading.
- (void)viewDidLoad {
    pageNumberLabel.text = [NSString stringWithFormat:@\"Page %d\", pageNumber + 1];
}



- (void)dealloc {
    [pageNumberLabel release];
    [numberImage release];

    [super dealloc];
}


@end