UICollection View Flow Layout Vertical Align

Question

By default, when you are using the flow layout in a collection view, cells are centered vertically. Is there a way to change this alignment ?

Answer 1

This may or may not work for your particular situation, but I had some luck subclassing UICollectionViewFlowLayout in the following way:

@interface CustomFlowLayout : UICollectionViewFlowLayout
@end

@implementation CustomFlowLayout

- (NSArray *)layoutAttributesForElementsInRect:(CGRect)rect{
    NSArray* attributesToReturn = [super layoutAttributesForElementsInRect:rect];
    for (UICollectionViewLayoutAttributes* attributes in attributesToReturn) {
        if (nil == attributes.representedElementKind) {
            NSIndexPath* indexPath = attributes.indexPath;
            attributes.frame = [self layoutAttributesForItemAtIndexPath:indexPath].frame;
        }
    }
    return attributesToReturn;
}

- (UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath {
    UICollectionViewLayoutAttributes *currentItemAttributes = [super layoutAttributesForItemAtIndexPath:indexPath];

    currentItemAttributes.frame = CGRectOffset(currentItemAttributes.frame, 0, 0.5 * CGRectGetHeight(currentItemAttributes.frame));

    return currentItemAttributes;
}

@end