iOS - UIScrollView is not working (it doesn't

Question

I would like to display an image (width: 320 pixels, height: 1250 pixels) in an image view.

When I compile the application I get no scrolling at all. The view stays fixed.

What I did:

1. Added an UIScrollView via Interface Builder to my view.
2. Added an UIImageView via Interface Builder to my view.
3. Verified that UIImageView is below UIScrollView in Interface Builder.
4. Set the size of the UIScrollView with ViewDidLoad.

How do I do this?

Code:

- (void)viewDidLoad
{
    [super viewDidLoad];
    scrollView.contentSize = CGSizeMake(320, 1250);
}

Screenshots:

ImageView:

ScrollView:

Answer 1

So for me the problem was that setting the content size didn't work in viewDidLoad(). I tried everything and I didn't understand why it wouldn't want to work, and then I tried the same stuff in viewDidAppear() and it magically worked...

Answer 2

I came across this same issue on iOS6 and the solution was to programmatically adjust the ContentSize. So I will just quote from Raja (above) to show this:

CGSize scrollViewContentSize = CGSizeMake(320, 400);
[self.scrollView setContentSize:scrollViewContentSize];

NOTE: I was not having this issue on iOS5.. seems like iOS6 decided to do alot of prank just like the rotation/orientation saga

Answer 3

I found I had a similar problem but none of the above code worked. The issue was due to autolayout. I found that if I turned off autolayout by going to the storyboard clicking on Utilities -> File Inspector and unchecked Use Autolayout the scrolling did work (I also set scroll.contentSize = ...).

Answer 4

CGRect scrollViewFrame = CGRectMake(0, 0, 320, 400);
self.scrollView = [[UIScrollView alloc] initWithFrame:scrollViewFrame];

[self.view addSubview:self.scrollView];
CGSize scrollViewContentSize = CGSizeMake(320, 400);
[self.scrollView setContentSize:scrollViewContentSize];
scrollView.delegate = self;

[self.scrollView setBackgroundColor:[UIColor blackColor]];
[scrollView setCanCancelContentTouches:NO];

scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;
scrollView.clipsToBounds = YES;
scrollView.scrollEnabled = YES;
scrollView.pagingEnabled = YES;

NSUInteger nimages = 0;
CGFloat cx = 0;
for (; ; nimages++) {
    NSString *imageName = [NSString stringWithFormat:@"image%d.jpg", (nimages + 1)];
    UIImage *image = [UIImage imageNamed:imageName];
    if (image == nil) {
        break;
    }
    UIImageView *imageView = [[UIImageView alloc] initWithImage:image];

    CGRect rect = imageView.frame;
    rect.size.height = image.size.height;
    rect.size.width = image.size.width;
    rect.origin.x = ((scrollView.frame.size.width - image.size.width) / 2) + cx;
    rect.origin.y = ((scrollView.frame.size.height - image.size.height) / 2);

    imageView.frame = rect;

    [scrollView addSubview:imageView];
    [imageView release];

    cx += scrollView.frame.size.width;
}


[scrollView setContentSize:CGSizeMake(cx, [scrollView bounds].size.height)];

Answer 5

Just add code

scrollView.contentSize = CGSizeMake(WIDTH,HEIGHT);

to method -(void)viewDidLayoutSubviews. For more information checkout Stanford CS193p Lecture No 8 to understand View Controller Life cycle.