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

This code will prevent unnecessary animation and maintain the scroll view's content offset, it worked fine for me.

let lastScrollOffset = tableView.contentOffset
tableView.beginUpdates()
tableView.reloadData()
tableView.endUpdates()
tableView.layer.removeAllAnimations()
tableView.setContentOffset(lastScrollOffset, animated: false)

Answer 2

I am showing if only one row is being added. You can extend it to multiple rows.

    // dataArray is your data Source object
    [dataArray insertObject:name atIndex:0];
    CGPoint contentOffset = self.tableView.contentOffset;
    contentOffset.y += [self tableView:self.tableView heightForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0]];
    [self.tableView reloadData];
    [self.tableView setContentOffset:contentOffset];

But for this to work you need to have defined - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath the method. Or else, you can directly give your tableview row height if it is constant.

Answer 3

In iOS 12.x, using Xcode 10.2.1, an easier option is.

UIView.performWithoutAnimation { 
    let loc = tableView.contentOffset
    tableView.reloadRows(at: [indexPath], with: .none)
    tableView.contentOffset = loc
}

This works better than following; it shakes at times when the row is not fully visible.

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

Answer 4

i wrote something that works perfect for me:

extension UIScrollView {
    func reloadDataAndKeepContentOffsetInPlace(reloadData:(() -> Void)) {
    let currentContentHeight = contentSize.height
    if currentContentHeight == .zero {
       reloadData()
       return
    }
    reloadData()
    layoutIfNeeded()
    let newContentHeight = self.contentSize.height
    DispatchQueue.main.async {
        var contentOffset = self.contentOffset
        contentOffset.y += newContentHeight - currentContentHeight
        self.setContentOffset(contentOffset, animated: false)
    }
  }
}

use like this:

   self.reloadSomeData()
   collectionView.reloadDataAndKeepContentOffsetInPlace { [weak self] in
                                guard let self = self else { return }
                                self.collectionView.reloadData()
                            }

Answer 5

try to replace

reloadData with

tableView.reloadRows(at: tableView!.indexPathsForVisibleRows!, with: .none),

but you should be care about no cells, if no cells, this method should cause crash.

Answer 6

Swift 4.2 : Simple Solution

override func viewDidLoad() {
 super.viewDidLoad()

 self.tableView.estimatedRowHeight = 0
 self.tableView.estimatedSectionHeaderHeight = 0
 self.tableView.estimatedSectionFooterHeight = 0
}

//And then simply update(insert, reloadSections, delete etc) your tableView or reload

tableView.reloadData()

//or

UIView.performWithoutAnimation {

  tableView.beginUpdates()
  .....
  tableView.endUpdates()
}