How to focus last cell in the UITableview in ios - ios

Question

I am creating a chat interface.
User's message is put in a new UITable view cell.
And when update the table view, I use the following code.
extension UITableView {
func scrollToBottom() {
let rows = self.numberOfRows(inSection: 0)
if rows > 0 {
let indexPath = IndexPath(row: rows - 1, section: 0)
self.scrollToRow(at: indexPath, at: .bottom, animated: true)
}
}
}
Actually this works a little better, but there is something strange.
When I turn off the app and turn it on again, or after exiting the screen and entering again, the following issues arise.
The issue is that when I add a new cell, it goes up to the first cell in the table view and back down to the last cell.
See the issue(https://vimeo.com/266821436)
As the number of cells increases, the scrolling becomes too fast and too messy.
I just want to keep updating the last cell that is newly registered.
What should I do?

Answer 1

Please use DispatchQueue to Scroll because of the method you are fire is executed with tableView load data so we need to give time to scroll.
extension UITableView {
func scrollToBottom() {
let rows = self.numberOfRows(inSection: 0)
if rows > 0 {
DispatchQueue.main.async {
let indexPath = IndexPath(row: rows - 1, section: 0)
self.scrollToRow(at: indexPath, at: .bottom, animated: true)
}
}
}
}
or
func scrollToBottom(){
DispatchQueue.main.async {
let indexPath = IndexPath(row: self.array.count-1, section: 0)
self.tableView.scrollToRow(at: indexPath, at: .bottom, animated: true)
}
}

Answer 2

self.scrollToRow(at: indexPath.last ...)