title: collectionViewLayout sizeForItemAtIndexPath makes the view look blank
body: <p>I´m trying to implement a CollectionViewController, where the images sizes are shown correctly. But when I implement the method "collectionViewLayout sizeForItemAtIndexPath", none of the images are shown. Does anybody know why? Here is my CollectionViewController code:</p>
  
  <pre><code>#import "PhotosViewController1.h"
  
  @interface PhotosViewController1 ()
  
  @end
  
  @implementation PhotosViewController1
  
  
  - (void)viewDidLoad
  {
  
      [super viewDidLoad];
      _carImages = [@[@"Wild-Love.jpg",
                    @"d919004663f99c934b20c1bd46fcad3e.jpg",
  
                    @"164_v-viergalerie.jpg"] mutableCopy];
  }
  
  - (void)didReceiveMemoryWarning
  {
      [super didReceiveMemoryWarning];
      // Dispose of any resources that can be recreated.
  }
  
  
  #pragma mark -
  #pragma mark UICollectionViewDataSource
  
  -(NSInteger)numberOfSectionsInCollectionView:
  (UICollectionView *)collectionView
  {
      return 1;
  }
  
  -(NSInteger)collectionView:(UICollectionView *)collectionView
      numberOfItemsInSection:(NSInteger)section
  {
      return _carImages.count;
  }
  
  -(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView
                   cellForItemAtIndexPath:(NSIndexPath *)indexPath
  {
      PhotosCell *myCell = [collectionView
                                      dequeueReusableCellWithReuseIdentifier:@"MyCell"
                                      forIndexPath:indexPath];
  
      UIImage *image;
      int row = [indexPath row];
  
      image = [UIImage imageNamed:_carImages[row]];
  
      myCell.imageView.image = image;
  
      return myCell;
  }
  
  
  #pragma mark -
  #pragma mark UICollectionViewFlowLayoutDelegate
  
  -(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
  {
      UIImage *image;
      int row = [indexPath row];
  
      image = [UIImage imageNamed:_carImages[row]];
  
      return image.size;
  }
  
  
  @end
  </code></pre>