title: Memory Warning and crash because of UIImageView with Storyboard
body: <p>I have a catalog application on IOS 6. So there are some UIImageView in each view. </p>
  
  <p>I think, when I pass to other views, old imageviews are not released. So my Real Mem. becomes 300MB and Virtual Mem. becomes 500MB and I am getting Memory Warning.</p>
  
  <p>I used to use </p>
  
  <pre><code>- (void)viewDidUnload
  {
      [super viewDidUnload];
      itemImageView = nil;
      scrollView = nil;
  }
  </code></pre>
  
  <p>What should I do more? Am I missing something usual?</p>
  
  <p>Update:</p>
  
  <p>I am initializing ImageView like this:</p>
  
  <pre><code>    __block UIImageView *imageview = [[UIImageView alloc] init];
  </code></pre>
  
  <p>and set it via AFNetworking:</p>
  
  <pre><code> AFImageRequestOperation *operation = [AFImageRequestOperation imageRequestOperationWithRequest:imageRequest
                                                                                    imageProcessingBlock:nil
                                                                                               cacheName:@"nscache"
                                                                                                 success:^(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image){
                                                                                                     imageview.image = image;
                                                                                                 }
                                                                                                 failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error){ NSLog([error description]); }
                                                ];
  </code></pre>
  
  <p>Update:</p>
  
  <p>I am using storyboard. So from one view to other, I am using Segue. If I go back to first controller, viewDidUnload for the second controller is not called. If I go to second view again, memory increases, which means all the image views in the second view are loaded again. Where am I wrong?</p>
  
  <p>Update 2:
  I am starting to believe that, it is about Storyboard and Push segue. To go back to the first view, I am using push segue. I create another custom segue that pops the second viewcontroller.</p>