Question

I have a swipe recognizer attached to cells in my table view

- (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];

      //swipe recognition
        UISwipeGestureRecognizer *g = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(cellWasSwiped:)];
        [cell addGestureRecognizer:g];
        [g release];


    }


    // Configure the cell...
    [[cell textLabel] setText:[NSString stringWithFormat:@" number %d", indexPath.row]];
    return cell;
}

and the swipe function is

- (void)cellWasSwiped:(UIGestureRecognizer *)g {
    NSLog(@"sunt in cellWasSwiped");
    swipeViewController *svc = [[swipeViewController alloc]init];
  [self.navigationController pushViewController:svc animated:YES];
  [svc release];
}

and by introducing breakpoints i see that my swipe function is called 2 times and there are two identical view controllers pushed on my navigation controller. Why is my swipe function called twice when i swipe a cell?

Answer 1

Your cellWasSwiped can be called multiple times on change of UIGestureRecognizer state. You need to check property state, it will be UIGestureRecognizerStateEnded when user finished his action. It’s also good to check for states UIGestureRecognizerStateFailed and UIGestureRecognizerStateCancelled.