UITableView, UICollectionView scroll to top

Question

UITableView and UICollectionView is able to scroll to top when you tap on top of the screen. Am I able to call this action from code? Or is there any other way to scroll to top of UITableView / UICollectionView?

I tried scrollToRow function, table scrolls to top, but navbar title remains small. I want to have it as big nav bar title like on load of viewController.

https://stackoverflow.com/questions/724892/uitableview-scroll-to-the-top Related? — Ahmad F, May 23 '18 at 08:52
Just set tableView/scrollView.setContentOffset(.zero, animated:true/false) — Sti, May 23 '18 at 08:57
@AhmadF I saw this post, but I did not find solution. With every try I still have problem like with scrollToRow. — Lifeplus, May 23 '18 at 08:59
You might need to treat it as a *scroll view* instead of a table view, don't scroll to a row, try to scroll to the top content size... — Ahmad F, May 23 '18 at 09:09

LinusGeffarth · Answer 1 · 2018-06-05T09:52:17.813

You can do something like this:

tableView.scrollView.scroll(to: .top)
collectionView.scrollView.scroll(to: .top)

...using the following extension that allows for several different scroll positions:

extension UIScrollView {
    enum Position {
        case top
        case center
        case bottom
    }
    /// Scrolls scroll view to y position passed, animated
    func scroll(to position: Position, animated: Bool = true) {
        switch position {
        case .top:
            self.setContentOffset(CGPoint(x: 0, y: -contentInset.top), animated: animated)
        case .center:
            self.setContentOffset(CGPoint(x: 0, y: contentSize.height/2-self.frame.height/2), animated: animated)
        case .bottom:
            self.setContentOffset(CGPoint(x: 0, y: contentSize.height-self.frame.height), animated: animated)
        }
    }
    /// Scrolls scroll view to y value passed, animated
    func scroll(to position: CGFloat, animated: Bool = true) {
        self.setContentOffset(CGPoint(x: 0, y: position), animated: animated)
    }

    /// Scrolls scroll view by y value passed, animated
    func scroll(by position: CGFloat, animated: Bool = true) {
        self.setContentOffset(CGPoint(x: 0, y: self.contentOffset.y + position), animated: animated)
    }

    func scroll(to view: UIView, animated: Bool = true) {
        self.setContentOffset(CGPoint(x: 0, y: view.frame.maxY), animated: animated)
    }
}

score 1 · Answer 2 · answered May 23 '18 at 09:11

1

use below line:

tableView.setContentOffset(.zero, animated: true)

answered May 23 '18 at 09:11

Moayad Al kouz

1,342
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same problem as with scrollToRow function – Lifeplus May 23 '18 at 09:13

UITableView, UICollectionView scroll to top

2 Answers2