CODEWITHSUNDEEP
iphoneobjective-ciosuitableview
HighFlyingFantasy
HighFlyingFantasy

Reputation: 3789

Force UITableView to scroll to top?

How would you go about forcing a UITableViewCell to scroll to the top if the tableview contains less than 10 or so cells? I support editing of Managed Object Contexts within my tableView cells while the tableview is in editing mode. Needless to say, if a cell is at the bottom of the tableview, it gets blocked by the keyboard when a user goes to edit the title or location of an event. I tried a solution like:

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath*)indexPath
{
    [tableView deselectRowAtIndexPath:indexPath animated:NO];

    if(_selectedIndex == indexPath.row){
        _selectedIndex = -1;
        [tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
                         withRowAnimation:UITableViewRowAnimationFade];
        return;
    }

    if(_selectedIndex >= 0){
        NSIndexPath *previous = [NSIndexPath indexPathForRow:_selectedIndex inSection:0];
        _selectedIndex = indexPath.row;
        [tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:previous]
                         withRowAnimation:UITableViewRowAnimationFade];
    }

    _selectedIndex = indexPath.row;
    [tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
                     withRowAnimation:UITableViewRowAnimationFade];

    [tableView setContentOffset:CGPointMake(0, [tableView rowHeight]*indexPath.row) animated:YES];
}

But this does not keep the tableview at the contentOffset. it will snap to the top and then snap back

Upvotes: 3

Views: 12179

Answers (8)

Preeti Tiwari
Preeti Tiwari

Reputation: 1

More specified answer to your question:

extension UITableView {

    func scrollToBottom(){

        DispatchQueue.main.async {
            let indexPath = IndexPath(
                row: self.numberOfRows(inSection:  self.numberOfSections -1) - 1, 
                section: self.numberOfSections - 1)
            self.scrollToRow(at: indexPath, at: .bottom, animated: true)
        }
    }

    func scrollToTop() {

        DispatchQueue.main.async {
            let indexPath = IndexPath(row: 0, section: 0)
            self.scrollToRow(at: indexPath, at: .top, animated: false)
        }
    }
}

Upvotes: 0

Preeti Tiwari
Preeti Tiwari

Reputation: 1

It will be helpful to scroll to top your tableView

tableView.setContentOffset(CGPoint(x: 0, y: -tableView.contentInset.top), animated: true).

Upvotes: 0

Sagar Thukral
Sagar Thukral

Reputation: 70

This works in my case, also it scrolls to headear's top If you have:

  **myTablView.scrollRectToVisible((myTablView.rectForHeader(inSection: 0), to: myTablView.superview).0, animated: true)**

https://developer.apple.com/documentation/uikit/uitableview/1614872-rectforheader

Upvotes: 0

banumelody
banumelody

Reputation: 21

Have you try this? : 

- (void)scrollToRowAtIndexPath:(NSIndexPath *)indexPath atScrollPosition:(UITableViewScrollPosition)scrollPosition animated:(BOOL)animated;

The sample is:

[tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0] atScrollPosition:0 animated:YES];

Upvotes: 0

itsji10dra
itsji10dra

Reputation: 4675

UITableView is a subclass of UIScrollView, so you can also use:

[mainTableView scrollRectToVisible:CGRectMake(0, 0, 1, 1) animated:YES];

Upvotes: 2

Kyle Clegg
Kyle Clegg

Reputation: 39480

I like the following solution because it also scrolls to the top of a header view if you have one.

[self.tableView setContentOffset:CGPointZero animated:YES];

Upvotes: 12

Cliff Ribaudo
Cliff Ribaudo

Reputation: 9039

You probably should use this method on UITableView:

-(void)scrollToRowAtIndexPath:(NSIndexPath *)indexPath atScrollPosition:(UITableViewScrollPosition)scrollPosition animated:(BOOL)animated

Essentially what you do is that when the [tableView:didSelectRowAtIndexPath:] method of your UITableViewDelegate gets called, you pass the index of that selection to the above method and set scrollposition = UITableViewScrollPositionTop.

That will scroll the selected cell to the top of the screen and out of the way of the keyboard.

Upvotes: 4

Dima
Dima

Reputation: 23634

Have you consider sliding the whole tableview up?

edit: I did find something that looks like it does what you're looking for: Code here.

This code shrinks the inset of the table view from the bottom, which then allows it display one of those lower cells without snapping back down.

Upvotes: 2

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