When user uses back button to UITableView to scroll to last selected row

问题

I have a tableView with about 200 rows. When a user selects a row to view the details and later hits the back button, the tableView always returns to the top of the table.

I would like to set up the tableView to force the tableView to auto scroll to the row in which the user last selected.

How to do this?

回答1:

I would suggest storing selected NSIndexPath in the didSelectRowAtIndexPath method (when user presses on a cell). Then in viewWillAppear or viewDidAppear method (in view controller where your table view is) just call

tableView.scrollToRow(at: selectedIndexPath, at: .top, animated: true)

It will then scroll your table view to previously selected cell.

回答2:

you called any webservice call or reloadData in viewWillAppear, or viewDidAppear just remove that webservicecall/reloadData from viewWillAppear, or viewDidAppear automatically it shows last selected cell in tableview.

or the alternate Way

savedScrollPosition means save your selected Index on didselectRow

yourTableView.scrollToRow(at: IndexPath(row: savedScrollPosition, section: 0), atScrollPosition: .top, animated: false)
var point = yourTableView.contentOffset
point.y -= yourTableView.rowHeight
yourTableView.contentOffset = point

回答3:

Save the last seleted row in NSUserDefaults and use UITableView "scrollToRowAtIndexPath" as follows:

Objective- C:

[self.tableView scrollToRowAtIndexPath:lastSelectedIndex atScrollPosition:UITableViewScrollPositionMiddle animated:YES];

Swift:

self.tableView.scrollToRowAtIndexPath(lastSelectedIndex, atScrollPosition: UITableViewScrollPosition.Bottom, animated: true)

Use this after UITableView is reloaded.

回答4:

I think you should find out what cause the table scroll to top. Also You can save the selected indexPath to scroll to the row in which the user last selected.

来源：https://stackoverflow.com/questions/40970176/when-user-uses-back-button-to-uitableview-to-scroll-to-last-selected-row