Scroll UICollectionView to bottom

Question

I would like to scroll the UICollectionView to the bottom so the last item is in the view. I have tried to use scrollToItemAtIndexPath but it does not seem to be working. I want

Answer 1

For Swift 3 and multiple sections

/**

 This method scrolls the *UICollectionView* to the last item in the last section

 */

func scrollToLastItem() {

    let lastSection = collectionView.numberOfSections - 1

    let lastRow = collectionView.numberOfItems(inSection: lastSection)

    let indexPath = IndexPath(row: lastRow - 1, section: lastSection)

    self.collectionView.scrollToItem(at: indexPath, at: .right, animated: true)

}

Answer 2

I have added the lines below to run once the query is complete.

var item = self.collectionView(self.collectionView!, numberOfItemsInSection: 0) - 1
var lastItemIndex = NSIndexPath(forItem: item, inSection: 0)
self.collectionView?.scrollToItemAtIndexPath(lastItemIndex, atScrollPosition: UICollectionViewScrollPosition.Top, animated: false)

Update to Swift 5

let item = self.collectionView(self.collectionView, numberOfItemsInSection: 0) - 1
let lastItemIndex = IndexPath(item: item, section: 0)
self.collectionView.scrollToItem(at: lastItemIndex, at: .top, animated: true)

Answer 3

You can track top and bottom of your visible view and load next page of items

  func scrollViewDidScroll(_ scrollView: UIScrollView) {

    if (scrollView.contentOffset.y >= (scrollView.contentSize.height - scrollView.frame.size.height)) {
        print("bottom")
    }

    if (scrollView.contentOffset.y <= 0) {
        print("top")
    }
}

Answer 4

For Swift -

For Horizontal Scrolling - .right

For Vertical Scrolling - .bottom

override func viewDidLayoutSubviews() {
        let section = 0
        let lastItemIndex = self.dateCollectionView.numberOfItemsInSection(section) - 1
        let indexPath:NSIndexPath = NSIndexPath.init(forItem: lastItemIndex, inSection: section)
        self.dateCollectionView.scrollToItemAtIndexPath(indexPath, atScrollPosition: .right, animated: false)
    }

Answer 5

Update for Swift 3

func viewScrollButton() {
    let lastItem = collectionView(self.collectionView!, numberOfRowsInSection: 0) - 1
    let indexPath: NSIndexPath = NSIndexPath.init(item: lastItem, section: 0)
    self.collectionView.scrollToRow(at: indexPath as IndexPath, at: .bottom, animated: false)
}

Answer 6

Swift 4:

For Horizontal Scrolling - .right

For Vertical Scrolling - .bottom

let lastItemIndex = self.collectionView.numberOfItems(inSection: 0) - 1
let indexPath:IndexPath = IndexPath(item: lastItemIndex, section: 0)
self.collectionView.scrollToItem(at: indexPath, at: .right, animated: false)