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

Swift 5 & 4 Just Call this Function when you want to display the last cell of collectionview

//MARK:- Collection view Scroll to End
func funColvScrollToEnd()
{
    let item = self.collectionView(self.colv!, numberOfItemsInSection: 0) - 1
    let lastItemIndex = NSIndexPath(item: item, section: 0)
    self.colv?.scrollToItem(at: lastItemIndex as IndexPath, at: .bottom, animated: false)
}
//MARK:- You can use .right/ .left/ .top/ .bottom  

Answer 2

Swift 4

collectionView?.scrollToItem(at: IndexPath(item: 3, section: 0), at: UICollectionViewScrollPosition.top, animated: false)

Answer 3

Updated for Swift 3:

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

Answer 4

    lstMessages.reloadData()
    let item = self.collectionView(lstMessages, numberOfItemsInSection: 0) - 1
    let lastItemIndex = NSIndexPath(forItem: item, inSection: 0)
    lstMessages.scrollToItemAtIndexPath(lastItemIndex, atScrollPosition: UICollectionViewScrollPosition.Top, animated: false)

Where lstMessages is my collectionView

Answer 5

Swift 4.2

let lastSection = self.messagesCollectionView.numberOfSections - 1
let lastRow = self.messagesCollectionView.numberOfItems(inSection: lastSection)
let indexPath = IndexPath(row: lastRow - 1, section: lastSection)
self.messagesCollectionView.scrollToItem(at: indexPath, at: UICollectionView.ScrollPosition.top, animated: true)

Answer 6

Here's my take in Swift5:

extension UICollectionView {

    public func scrollToLastItem(at scrollPosition: UICollectionView.ScrollPosition, adjustment: CGFloat = 0.0, withAdjustmentDuration duration: TimeInterval = 0.5) {
        let lastSection = self.numberOfSections - 1
        let lastRowInLastSection = self.numberOfItems(inSection: lastSection)
        if lastSection > 0, lastRowInLastSection > 0 {
            let indexPath = IndexPath(row: lastRowInLastSection - 1, section: lastSection)
            let visibleIndexPaths = self.indexPathsForVisibleItems
            if !visibleIndexPaths.contains(indexPath) {
                self.self.scrollToItem(at: indexPath, at: scrollPosition, animated: true)
                UIView.animate(withDuration: duration) {
                    switch scrollPosition {
                    case .top, .bottom, .centeredVertically:
                        self.contentOffset.y += adjustment
                    case .left, .right, .centeredHorizontally:
                        self.contentOffset.x += adjustment
                    default:
                        print("Inavlid scrollPosition: \(scrollPosition)")
                    }
                }
            }
        }
    }
}