save selected row in UITableView after reloadData

Question

I write custom jabber client in iphone.

I use xmppframework as engine.

And I have UITableViewController with NSMutableArray for repesent contact list.

When i receive(or somebody change it contents) roster (aka contact list) i wanna change UITableView items (add/remove/modify). So if User work with listView at time when list updates by

[items addObject:newItem];
[self.tableView reloadData];

user lost current selection item.

So, my question is howto save (if possible, i mean if given selected item not removed) current select item after reloadData?

Thx.

Answer 1

The easy way is something like this:

NSIndexPath *ipath = [self.tableView indexPathForSelectedRow];
[self.tableView reloadData];
[self.tableView selectRowAtIndexPath:ipath animated:NO scrollPosition:UITableViewScrollPositionNone];

Answer 2

Adding a bit to Marco's answer:

First, if you're using multiple selection, you can add this method to your ViewController and call it whenever you need to call [tableView reloadData]:

- (void)reloadTableView
{
    NSArray *indexPaths = [self.tableView indexPathsForSelectedRows];
    [self.tableView reloadData];
    for (NSIndexPath *path in indexPaths) {
        [self.tableView selectRowAtIndexPath:path animated:NO scrollPosition:UITableViewScrollPositionNone];
    }
}

Second, if you're in a UITableViewController and you want to preserve selection after tableView appears there's a feature in UITableViewController: clearsSelectionOnViewWillAppear you can turn on or off.

See here: http://developer.apple.com/library/ios/#documentation/uikit/reference/UITableViewController_Class/Reference/Reference.html

Answer 3

Swift 4.2 Tested

The correct way to update selected rows after reload table view is:

let selectedRows = tableView.indexPathsForSelectedRows

tableView.reloadData()

DispatchQueue.main.async {
    selectedRows?.forEach { selectedRow in
        tableView.selectRow(at: selectedRow, animated: false, scrollPosition: .none)
    }
}

Answer 4

The workaround is to use reloadSections: instead of reloadData. For some reason reloadData removes the current selection.