[Solved] AutoScrolling with zooming image in iphone

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- (void)viewDidLoad
{
 [super viewDidLoad];

// 1
   UIImage *image = [UIImage imageNamed:@"photo1.png"];
   self.imageView = [[UIImageView alloc] initWithImage:image];
   self.imageView.frame = (CGRect){.origin=CGPointMake(0.0f, 0.0f), .size=image.size};
  [self.scrollView addSubview:self.imageView];

// 2
   self.scrollView.contentSize = image.size; 
  }

viewDidLoad

  1. First, you need to create an image view with the photo1.png image you added to your project and you set the image view frame (it’s size
    and position) so it’s the size of the image and sits at point 0,0
    within the parent. Finally, the image view gets added as a subview of
    your scroll view.

  2. You have to tell your scroll view the size of the content contained within it, so that it knows how far it can scroll
    horizontally and vertically. In this case, it’s the size of the image.

- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];

// 1
CGRect scrollViewFrame = self.scrollView.frame;
CGFloat scaleWidth = scrollViewFrame.size.width / self.scrollView.contentSize.width;
CGFloat scaleHeight = scrollViewFrame.size.height / self.scrollView.contentSize.height;
CGFloat minScale = MIN(scaleWidth, scaleHeight);
self.scrollView.minimumZoomScale = minScale;

// 2
self.scrollView.maximumZoomScale = 1.0f;
self.scrollView.zoomScale = minScale;

}

viewWillAppear

  1. Next, you need to work out the minimum zoom scale for the scroll view. A zoom scale of one means that the content is displayed at
    normal size. A zoom scale below one shows the content zoomed out,
    while a zoom scale of greater than one shows the content zoomed in.

  2. You set the maximum zoom scale as 1, because zooming in more than the image’s resolution can support will cause it to look blurry. You
    set the initial zoom scale to be the minimum, so that the image starts
    fully zoomed out.

solved AutoScrolling with zooming image in iphone