Zoomscale UIScrollView not working - ios

Question

I create PhotoViewer by using UICollectionView scroll direction holizontal, pagingEnable = true. I create UICollectionViewCell contains UIScrollView to zooming UIImage.
But the first create UICollectionViewCell zoomScale working, UICollectionCell reuse zoomScale not working.
My code:
#interface ImageCell : UICollectionViewCell
#property (nonatomic, strong) UIImageView *imgView;
#property (nonatomic, strong) IBOutlet UIScrollView *scrollView;
#property (nonatomic, strong) NSString *stringURL;
#property (nonatomic, strong) UIImage *img;
- (void)resize;
#end
#interface ImageCell()<UIScrollViewDelegate>
#end
#implementation ImageCell
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
return self;
}
- (void)resize {
SDWebImageManager *manager = [SDWebImageManager sharedManager];
[manager downloadWithURL:[NSURL URLWithString:self.stringURL]
options:0
progress:^(NSInteger receivedSize, NSInteger expectedSize)
{
// progression tracking code
}
completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, BOOL finished) {
if (image) {
if(self.imgView == nil) {
self.imgView = [[UIImageView alloc] initWithFrame:self.frame];
[self.scrollView addSubview:self.imgView];
}
NSLog(#"%#", NSStringFromCGSize(image.size));
self.img = image;
self.imgView.frame = CGRectMake(0, 0, image.size.width, image.size.height);
self.imgView.image = image;
self.scrollView.contentSize = image.size;
CGRect scrollViewFrame = self.scrollView.frame;
CGFloat scaleWidth = scrollViewFrame.size.width / image.size.width;
CGFloat scaleHeight = scrollViewFrame.size.height / image.size.height;
CGFloat minScale = MIN(scaleWidth, scaleHeight);
self.scrollView.minimumZoomScale = minScale;
self.scrollView.maximumZoomScale = 1;
[self.scrollView setZoomScale:minScale];
[self centerScrollViewContents];
}
}];
}
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.imgView;
}
[self.scrollView setZoomScale:minScale]; working when cell is create, when cell reuse not working

Answer 1

This line from the UIScrollView class reference
The UIScrollView class can have a delegate that must adopt the UIScrollViewDelegate protocol. For zooming and panning to work, the delegate must implement both viewForZoomingInScrollView: and scrollViewDidEndZooming:withView:atScale:
So you should also implement method scrollViewDidEndZooming:withView:atScale: