UITableView Refresh without scrolling

Question

I have a _TableView with items , and I want to set automatic refresh,and I don\'t want it to scroll on refresh , lets say user scrolled 2 pages down , and the refre

Answer 1

When you want to reload you have to

self.tableView.reloadData()

self.tableView.layoutIfNeeded()

and also use this UITableViewDelegate

func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
        return 'your maximum cell's height'
}

and your tableView will remain on the previous scroll position without scrolling

Answer 2

SWIFT 3

let contentOffset = self.tableView.contentOffset
self.tableView.reloadData()
self.tableView.layoutIfNeeded()
self.tableView.setContentOffset(contentOffset, animated: false)

This is error of iOS8 when using UITableViewAutomatic Dimension. We need store the content offset of table, reload table, force layout and set contenOffset back.

CGPoint contentOffset = self.tableView.contentOffset;
[self.tableView reloadData];
[self.tableView layoutIfNeeded];
[self.tableView setContentOffset:contentOffset];

Answer 3

Just set estimatedRowHeight to maximum possible value.

 self.tableView.estimatedRowHeight = 1000
 self.tableView.estimatedSectionFooterHeight = 100.0
 self.tableView.estimatedSectionHeaderHeight = 500.0

That's it!!

Note:

Please do not use FLT_MAX, DBL_MAX value. May be it will crash your app.

Answer 4

I'm doing it this way:

messages.insertContentsOf(incomingMsgs.reverse(), at: 0)
table.reloadData()

// This is for the first load, first 20 messages, scroll to bottom
if (messages.count <= 20) {
      let indexToScroll = NSIndexPath(forRow: saferSelf.messages.count - 1, inSection: 0)
      table.scrollToRowAtIndexPath(indexToScroll, atScrollPosition: .Top , animated: false)
}
// This is to reload older messages on top of tableview
else {
      let indexToScroll = NSIndexPath(forRow: incomingMsgs.count, inSection: 0)
      table.scrollToRowAtIndexPath(indexToScroll, atScrollPosition: .Top , animated: false)
      // Remove the refreshControl.height + tableHeader.height from the offset so the content remain where it was before reload
      let theRightOffset = CGPointMake(0, table.contentOffset.y - refreshControl.frame.height - table.headeView.frame.height)
      table.setContentOffset(theRightOffset, animated: false)
}

...also, since I use dynamic cell height, to avoid some weirdness, the estimation is cached:

var heightAtIndexPath = [NSIndexPath: CGFloat]()
func tableView(tableView: UITableView, estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    return heightAtIndexPath[indexPath] ?? UITableViewAutomaticDimension
}
func tableView(tableView: UITableView, willDisplayCell cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath) {
    heightAtIndexPath[indexPath] = cell.frame.height
}

Answer 5

For Swift 3+:

You need to save the current offset of the UITableView, then reload and then set the offset back on the UITableView.

I have created this function for this purpose:

func reload(tableView: UITableView) {

    let contentOffset = tableView.contentOffset
    tableView.reloadData()
    tableView.layoutIfNeeded()
    tableView.setContentOffset(contentOffset, animated: false)

}

Simply call it with: reload(tableView: self.tableView)

Answer 6

Use Extension

create UITableViewExtensions.swift and add following:

extension UITableView {

    func reloadDataWithoutScroll() {
        let offset = contentOffset
        reloadData()
        layoutIfNeeded()
        setContentOffset(offset, animated: false)
    }
}