How to make first cell visible?

Question

I' have a code which detects last cell, but I am curious how to detect now the very first cell in tableView, because in my tableView not all cells are visible on device like iphone 7 or less that is why i have to use scroll method.

    func scrollViewDidScroll(_ scrollView: UIScrollView) {
    
    let contentOffsetMaxY: Float = Float(scrollView.contentOffset.y + scrollView.bounds.size.height)
    let contentHeight: Float = Float(scrollView.contentSize.height)
    let lastCellIsVisible = contentOffsetMaxY > contentHeight
    
    
    if lastCellIsVisible {
     //some action
    }
}

https://stackoverflow.com/questions/724892/uitableview-scroll-to-the-top — Krishnarjun Banoth, May 08 '21 at 09:33
Does this answer your question? [UITableView - scroll to the top](https://stackoverflow.com/questions/724892/uitableview-scroll-to-the-top) — Alex Bailey, May 08 '21 at 17:00
@AlexBailey No, i don't need scrolling action to top, I want to know how to detect all cells with my code above at least for the first cell. I managed only for a last cell to be detected. And methods like `willDisplayCell` don't work — Montes, May 09 '21 at 10:53

score 0 · Answer 1 · answered May 07 '21 at 10:24

You can use tableView(_:willDisplay:forRowAt:) of UITableViewDelegate.

It will be called just before the cell is displayed, and will be called once for every cell.

Your code would look like this:


func viewDidLoad() {
  super.viewDidLoad()
  ...
  tableView.delegate = self
  ...
}

func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
  if indexPath.row == 0 {
    // First cell is going to be displayed
  }
  if indexPath.row == tableView.numberOfRows(inSection: indexPath.section) - 1 {
    // Last cell is going to be displayed
  }
}

How to make first cell visible?

1 Answers1