Custom accessory view button - wrong row selected - iphone

Question

I have implemented the accessory view of a UITableViewCell as a button, in the
button's selector method i have the following code
- (UIButton *) makeDetailDisclosureButton
{
UIButton * button = [UIButton buttonWithType:UIButtonTypeCustom];
UIImage* image = [UIImage imageNamed:#"custom.png"];
[button setImage:image forState:UIControlStateNormal];
button.frame = CGRectMake(0.0, 0.0, image.size.width, image.size.height);
[button addTarget: self
action: #selector(accessoryButtonTapped:withEvent:)
forControlEvents: UIControlEventTouchUpInside];
return ( button );
}
- (void) accessoryButtonTapped: (UIControl *)button withEvent:(UIEvent *) event
{
NSSet *touches = [event allTouches];
UITouch *touch = [touches anyObject];
CGPoint currentTouchPosition = [touch locationInView:self.tableView];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:currentTouchPosition];
if (indexPath != nil)
{
[self tableView: self.tableView accessoryButtonTappedForRowWithIndexPath: indexPath];
}
}
However sometimes the wrong row is being selected, ie if I tap on row 0 in the table i get
row = 1 actually being selected. The code above is quite well known as a solution for
a custom accessory view but it is proving unreliable. Is there something else i need to do here?

Answer 1

Try this,
- (void) accessoryButtonTapped: (UIControl *)button withEvent:(UIEvent *) event
{
UITableViewCell *cell = (UITableViewCell*)button.superview.superview;
NSIndexPath *indexPath = [self.tableView indexPathForCell:cell];
[self tableView:self.tableView accessoryButtonTappedForRowWithIndexPath:indexPath];
}
The idea here is pretty basic. Button's superview should give me cell.contentView and it's superview is the cell. There is lovely helper method indexPathForCell: which will give us the index path which we can use to pass to the delegate method.

Answer 2

Nothing wrong seen in your code but you can refer this tutorial for reference.
Difference I see in your code and in tutorial is
- (void) accessoryButtonTapped: (UIControl *)button withEvent:(UIEvent *) event //Your event
- (void)checkButtonTapped:(id)sender event:(id)event //In tutorial.
This does not make difference but still just a thought.
Hope it helps.

Answer 3

What do you have at tableView:accessoryButtonTappedForRowWithIndexPath: method?
Anyhow, I wouldn't mess with the touches to get the index path.
Instead I'd tag the button with the [indexPath row] and then pass the tag to the other method.

Answer 4

I had a similar problem: The index path row in tableView:accessoryButtonTappedForRowWithIndexPath: was consistently wrong for -- in my case -- every 5th row of the table view.
e.g., tapping the Detail Disclosure button for row 4 correctly gave me indexPath.row = 3; but tapping row 5 also gave me indexPath.row = 3.
My mistake related to having set incompatible row heights for my custom UITableViewCell.
i.e., I set the custom row height to 56 in the UITableViewCell's Size Inspector, but I forgot that I earlier had set the row height programmatically in tableView:heightForRowAtIndexPath: as a multiple of tableView.rowHeight. The default tableView.rowHeight (editable in the UITableView's Size Inspector) is 44, and that 'clash' apparently caused the problem.
I resolved my problem by setting the row height fields to 56 in the Size Inspectors of both the UITableView & the UITableViewCell and commenting out the tableView:heightForRowAtIndexPath: method.