UICollectoinView horizontal scroll with inter item spacing

Question

I am using a collection view for some of my images.

Each image should be displayed at the size of the screen, therefore one cell has the width of the screen. The

Answer 1

You should provide cell width by considering iterItemSpacing also. Try to provide cellWidth= 320-25=295. It should work then.

Answer 2

Okay, what I've found out is, that there are 2 options to achieve the proper scrolling.

1. UICollectionViewController size

Increasing the size of the collection view and it's items by adding exactly the value you need as interItemSpacing.

Here is some code:

- (void) setupCollectionView;
{
    PSTCollectionViewFlowLayout *flowLayout = [[PSTCollectionViewFlowLayout alloc] init];
    CGSize itemSize = self.view.bounds.size;
    itemSize.width +=25;
    [flowLayout setItemSize:itemSize];
    [flowLayout setScrollDirection:PSTCollectionViewScrollDirectionHorizontal];
    flowLayout.minimumInteritemSpacing = 0.0f;
    flowLayout.minimumLineSpacing = 0.0f;

    self.collectionView = [[PSTCollectionView alloc] initWithFrame:self.view.bounds
                                          collectionViewLayout:flowLayout];
    [self.collectionView registerClass:[AMDetailImageCell class]
        forCellWithReuseIdentifier:AMDetailImageCellIdentifier];
    self.collectionView.delegate = self;
    self.collectionView.dataSource = self;
    self.collectionView.pagingEnabled = YES;
    CGRect rectSize = self.view.bounds;
    rectSize.size.width +=25;
    self.collectionView.frame = rectSize;
    [self.view addSubview:self.collectionView];

    [self scrollToStartIndex];

}

2. SectionEdgeInset

Making one page = one section and using sectionEdgeInset would result in the same solution but is - for sure - not always an option!

Answer 3

I found a solution to it, and it involved subclassing the UICollectionViewFlowLayout.

My CollectionViewCell size is 302 X 457 and i set my minimum line spacing to be 18 (9pix for each cell)

When you extend from that class there are a few methods that need to be over-ridden. One of them is

• (CGSize)collectionViewContentSize

In this method, I needed to add up the total width of what was in the UICollectionView. That includes the ([datasource count] * widthOfCollectionViewCell) + ([datasource count] * 18)

Here is my custom UICollectionViewFlowLayout methods....

-(id)init
{
    if((self = [super init])){

       self.itemSize = CGSizeMake(302, 457);
       self.sectionInset = UIEdgeInsetsMake(10, 10, 10, 10);
       self.minimumInteritemSpacing = 0.0f;
       self.minimumLineSpacing = 18.0f;
       [self setScrollDirection:UICollectionViewScrollDirectionHorizontal];
   }
    return self;
}



-(CGSize)collectionViewContentSize{
   return CGSizeMake((numCellsCount * 302)+(numCellsCount * 18), 457);
}

This worked for me, so I hope someone else finds it useful!