How to scroll UITableView to specific position

How can I scroll the table's cell to specific position ? I have a table which shows 3 rows (according to height). what I want is if I click on 1st row than according to table's height the 1st row should scroll and get new position (center) 开发者_如何学编程and same for other rows. I tried contenOffset but did not work..

EDITED :

In short some thing like data picker when we select any row in picker the row scrolls to the center.

Thanks..

it should work using - (void)scrollToRowAtIndexPath:(NSIndexPath *)indexPath atScrollPosition:(UITableViewScrollPosition)scrollPosition animated:(BOOL)animated using it this way:

NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[yourTableView scrollToRowAtIndexPath:indexPath 
                     atScrollPosition:UITableViewScrollPositionTop 
                             animated:YES];

atScrollPosition could take any of these values:

typedef enum {
UITableViewScrollPositionNone,
UITableViewScrollPositionTop,
UITableViewScrollPositionMiddle,
UITableViewScrollPositionBottom
} UITableViewScrollPosition;

Swift 4.2 version:

let indexPath:IndexPath = IndexPath(row: 0, section: 0)
self.tableView.scrollToRow(at: indexPath, at: .none, animated: true)

Enum: These are the available tableView scroll positions - here for reference. You don't need to include this section in your code.

public enum UITableViewScrollPosition : Int {

case None
case Top
case Middle
case Bottom
}

DidSelectRow:

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

    let theCell:UITableViewCell? = tableView.cellForRowAtIndexPath(indexPath)

    if let theCell = theCell {
        var tableViewCenter:CGPoint = tableView.contentOffset
        tableViewCenter.y += tableView.frame.size.height/2

        tableView.contentOffset = CGPointMake(0, theCell.center.y-65)
        tableView.reloadData()
    }

}

[tableview scrollRectToVisible:CGRectMake(0, 0, 1, 1) animated:NO];

This will take your tableview to the first row.

finally I found... it will work nice when table displays only 3 rows... if rows are more change should be accordingly...

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{    
    return 1;
}


// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView 
 numberOfRowsInSection:(NSInteger)section
{  
    return 30;
}

- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil)
    {         
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault    
                                       reuseIdentifier:CellIdentifier] autorelease];
    }

    // Configure the cell.
    cell.textLabel.text =[NSString stringWithFormat:@"Hello roe no. %d",[indexPath row]];

    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell * theCell = (UITableViewCell *)[tableView     
                                              cellForRowAtIndexPath:indexPath];

    CGPoint tableViewCenter = [tableView contentOffset];
    tableViewCenter.y += myTable.frame.size.height/2;

    [tableView setContentOffset:CGPointMake(0,theCell.center.y-65) animated:YES];
    [tableView reloadData]; 
 }

Use [tableView scrollToRowAtIndexPath:indexPath atScrollPosition:scrollPosition animated:YES]; Scrolls the receiver until a row identified by index path is at a particular location on the screen.

And

scrollToNearestSelectedRowAtScrollPosition:animated:

Scrolls the table view so that the selected row nearest to a specified position in the table view is at that position.

It is worth noting that if you use the setContentOffset approach, it may cause your table view/collection view to jump a little. I would honestly try to go about this another way. A recommendation is to use the scroll view delegate methods you are given for free.

Simply single line of code:

self.tblViewMessages.scrollToRow(at: IndexPath.init(row: arrayChat.count-1, section: 0), at: .bottom, animated: isAnimeted)

In case, your table view only has one row and one section, you also can use following approach

 challengeInfoTableView.scrollRectToVisible(challengeInfoCell.challengeDescriptionTextView!.frame, animated: false)

In this case, you can directly scroll to the correct text field, text view, label etc.