sizeForItemAtIndexPath.m

#pragma mark Collection Layout Delegate
-(CGSize)collectionView:(UICollectionView *)collectionView
                 layout:(UICollectionViewLayout *)collectionViewLayout
 sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
    
    NSUInteger item = indexPath.item;
    if (item < [self.pageResult.results count] && indexPath.section == 0) {
      
      //------------ 重點 ------------ 
        NewsInfoCollectionViewCell *cell = (NewsInfoCollectionViewCell *) [collectionView cellForItemAtIndexPath:indexPath];
        if (cell == nil) {
            NSString *collectionViewCellClassName = NSStringFromClass(NewsInfoCollectionViewCell.class);
            
            cell = [[[NSBundle mainBundle] loadNibNamed:collectionViewCellClassName
                                                  owner:nil
                                                options:nil] firstObject];
        }
        
        [self renderCell:cell item:item];
        
        cell.contentView.bounds = CGRectMake(0, 0, self.screenWidth, 10);
        
        CGSize size = [cell systemLayoutSizeFittingSize:UILayoutFittingCompressedSize
                          withHorizontalFittingPriority:UILayoutPriorityDefaultHigh
                                verticalFittingPriority:UILayoutPriorityDefaultLow];
        
        return size;
      //------------ 重點結束 ------------ 
    }
    
    return [super collectionView:collectionView layout:collectionViewLayout sizeForItemAtIndexPath:indexPath];
}