title: UIScrollView not show image on iOS 9
body: <p>I've a problem with <code>UIScrollView</code>. It works perfectly on previous iOS version but not on iOS9.</p>
  
  <p>Here is my code</p>
  
  <pre><code>ProductHeaderCV *headerView = [collectionView dequeueReusableSupplementaryViewOfKind:
                                         UICollectionElementKindSectionHeader withReuseIdentifier:@"HeaderCV" forIndexPath:indexPath];
          headerView.delegate = self;
          headerView.catNameLabel.font  = [UIFont fontWithName:FONT_PSL size:14.0];
          headerView.sortNameLabel.font = [UIFont fontWithName:FONT_PSL size:14.0];
  
          //ScrollView
          [headerView.pageControl setNumberOfPages:[specialCateArray count]];
          headerView.pageControlScrollView.contentSize = CGSizeMake(320*[specialCateArray count], 180);
          headerView.pageControlScrollView.backgroundColor = [UIColor clearColor];
  
          float originX = 0;
  
          for(NSDictionary *dict in specialCateArray){
              NSString *img = [dict objectForKey:@"image"];
              UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(originX, 0, 320, 180)];
              imageView.contentMode = UIViewContentModeScaleAspectFit;
              [imageView setImageWithURL:[NSURL URLWithString:img] placeholderImage:nil];
  
              originX = originX+320;
              [headerView.pageControlScrollView addSubview:imageView];
          }
  </code></pre>
  
  <p>One more weird thing I've used the same code above and add it as subview on self <code>UIScrollView</code> (MainViewController) It's working without any problem.</p>
  
  <p>Please help.
  Thank you.</p>