UIScrollView Zoom does not work in iOS 7, but works fine in iOS 8

Question

I am scaling an image in a UIScrollView. On iPhone 4S with iOS 7, its operation does not work. But it works fine on iOS 8. Even in the simulator, it works fine on 4 with iOS 8. Any idea?

So I am returning the view in the delegate method as shown below,

#pragma mark UIScrollViewDelegate method
- (UIView *) viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return pictureView;
}

The hierarchy is used below

• UIScrollView
  • UIView (exit as PictureView)
    • UIImageView

Answer 1

" UIScrollView , UIScrollViewDelegate. viewForZoomingInScrollView: scrollViewDidEndZooming: withView: atScale:; , (maximumZoomScale) (minimumZoomScale) ."

https://developer.apple.com/library/prerelease/ios/documentation/UIKit/Reference/UIScrollView_Class/index.html#//apple_ref/occ/instp/UIScrollView/maximumZoomScale