Paging uiscrollview automatically scrolls to the first page

I've been working on a paging scrollview with several images and a tableview as a table of content. Using the table I can jump to specific pages. I've got everything working except the jump to page method which when I touch the screen brings the scroll view to the first page UNLESS I scroll to the next page. It's been driving me nuts for the last couple of days :s

here's my code :

-(void)skipToPage {     
    NSInteger temp = [selectedPage integerValue];   
    [pagingScrollView setContentOffset:
    [self offsetForPageAtIndex:temp] animated:NO];  
    pagingScrollView.contentSize = [self contentSizeForPagingScrollView]; 
}

- (CGPoint)offsetForPageAtIndex:(NSUInteger)index {                                                                                                        
    CGRect pagingScrollViewFrame = [self frameForPagingScrollView];                                                                                        
    CGPoint offset;                                                                                                                                        
    offset.x = (pagingScrollViewFrame.size.width * index);                                                                                                 
    offset.y = 0;                                                                                                                                          
    return offset;                                                                                                                                         
}  

Thanks in advance fellas!

EDIT: scrolviewDidScroll calls the Tile page method which prepares each image to be displayed

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    [self tilePages];   
}

It's a method from the photoScroller sample from Apple

- (void)tilePages 
{
    // Calculate which pages are visible
    CGRect visibleBounds = pagingScrollView.bounds;
    int firstNeededPageIndex = floorf(CGRectGetMinX(visibleBounds) / CGRectGetWidth(visibleBounds));
    int lastNeededPageIndex  = floorf((CGRectGetMaxX(visibleBounds)-1) / CGRectGetWidth(visibleBounds));
    firstNeededPageIndex = MAX(firstNeededPageIndex, 0);
    lastNeededPageIndex  = MIN(lastNeededPageIndex, [self imageCount] - 1);

    // Recycle no-longer-visible pages 
    for (ImageScrollView *page in visiblePages) {
        if (page.index < firstNeededPageIndex || page.index > lastNeededPageIndex) {
            [recycledPages addObject:page];
            [page removeFromSuperview];
        }
    }
    [visiblePages minusSet:recycledPages];

    // add missing pages
    for (int index = firstNeededPag开发者_如何学运维eIndex; index <= lastNeededPageIndex; index++) {
        if (![self isDisplayingPageForIndex:index]) {
            ImageScrollView *page = [self dequeueRecycledPage];
            if (page == nil) {
                page = [[[ImageScrollView alloc] init] autorelease];
            }
            [self configurePage:page forIndex:index];
            [pagingScrollView addSubview:page];
            [visiblePages addObject:page];
        }
    }

}

I got it working!

The problem is caused by the navigation controller which doesn't react well with the PhotoScroller sample app! to resolve it make the scrollview a subview of a standard UIView like:

UIView *view = [[UIView alloc] initWithFrame:pagingScrollViewFrame];
    [view addSubview:pagingScrollView];

    self.view = view;

Thanks :)

I am not totally sure what the problem is as you have described it. So my understanding of the issue you are seeing:

• When you click on the table view you are calling your skipToPage message, setting the content offset for the scroll view correctly and the correct page is shown?

• When you tap the view it jumps to the first page?

If you could clarify this sentence that might help:

except the jump to page method which when I touch the screen brings the scroll view to the first page UNLESS I scroll to the next page.

• What is the state of the app when you "touch the screen"?
• Are you touching the table view and then calling skipToPage?
• Is the tableview a subview of the scrollview on the first page?

So assuming this is what is happening (please correct me if I have missed something). Could you check what you are doing in the following messages (and post code):

(void)scrollViewDidScroll:(UIScrollView *)sender;
(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView;

If you were adjusting the content offset in those messages you might get unexpected behaviour from the scroll view.