Only one UITableViewCellAccessoryCheckmark allowed at a time

I have a tableview with a section that contains a list of sounds the user can "pick." Only the currently selected sound should show a UITableViewCellAccessoryCheckmark. Basically I got it working. However, when e.g. the bottom cell is checked, and I scroll up the table view (making the checked cell go out of view), and I check another cell, the check for the bottom (out of view) cell is not removed. Does anyone know why this is?

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";
    static NSString *TheOtherOne = @"OtherCell";
    static NSString *M开发者_Go百科iddleCell = @"MiddleCell";



    // Configure the cell...

    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
    NSString *theSound = [prefs objectForKey:@"pickedFailSound"];
    NSUInteger index = [failSounds indexOfObject:theSound];


    if (indexPath.section == 0){

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


        failAtLaunch = [[[UISwitch alloc] initWithFrame:CGRectMake(200, 7, 100, 30)] autorelease];
        [cell addSubview:failAtLaunch]; 
        cell.accessoryView = failAtLaunch; 
        cell.selectionStyle = UITableViewCellSelectionStyleNone;

        NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

        if(![prefs boolForKey:@"failAtLaunch"]) {
            [failAtLaunch setOn:NO animated:NO];
        } else {
            [failAtLaunch setOn:YES animated:NO];
        }

        [(UISwitch *)cell.accessoryView addTarget:self action:@selector(setIt) forControlEvents:UIControlEventValueChanged];
        cell.textLabel.text = @"Instafail";
        cell.detailTextLabel.text = @"Fail at Laucnh";

        return cell;

    } else if (indexPath.section == 1) {

        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MiddleCell];
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:MiddleCell] autorelease];
        }

        NSString *cellTitle = [failSounds objectAtIndex:indexPath.row];
        cell.textLabel.text = cellTitle;

        if (indexPath.row == index) {
            cell.accessoryType = UITableViewCellAccessoryCheckmark;
        }



        if ([cellTitle isEqualToString:@"Your Fail Sound"]){

            NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
            if(![prefs boolForKey:@"customSoundAvailable"]) {

                cell.selectionStyle = UITableViewCellSelectionStyleNone;
                cell.userInteractionEnabled = NO;
                cell.textLabel.textColor = [UIColor grayColor];
                cell.detailTextLabel.text = @"Record a Custom Failsound First";
            }
        } 

    return cell;

    } else {

        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:TheOtherOne];
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:TheOtherOne] autorelease];
        }


       cell.textLabel.text = @"Hold to record fail sound";
        UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
        btn.frame = CGRectMake(230.0f, 4.0f, 60.0f, 36.0f);
        [btn setTitle:@"OK" forState:UIControlStateNormal];
        [btn setTitle:@"OK" forState:UIControlStateSelected];
        [btn addTarget:self action:@selector(recordAudio) forControlEvents:UIControlEventTouchDown];
        [btn addTarget:self action:@selector(stop) forControlEvents:UIControlEventTouchUpInside];
        [cell.contentView addSubview:btn];


       return cell; 

      }     
    }

And:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{


    [tableView deselectRowAtIndexPath:indexPath animated:YES];

    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
    NSString *theSound = [prefs objectForKey:@"pickedFailSound"];
    NSUInteger index = [failSounds indexOfObject:theSound];

    //NSLog(@"The index is: %@", index);

    if (indexPath.section == 1){


                NSIndexPath *oldIndexPath = [NSIndexPath indexPathForRow:index inSection:1];

                NSLog(@"Oldindexpath is: %@", oldIndexPath);
                UITableViewCell *newCell = [tableView cellForRowAtIndexPath:indexPath];


                if (newCell.accessoryType == UITableViewCellAccessoryNone) {

                    newCell.accessoryType = UITableViewCellAccessoryCheckmark;
                }

                UITableViewCell *oldCell = [tableView cellForRowAtIndexPath:oldIndexPath];


                if (oldCell != newCell){

                    if (oldCell.accessoryType == UITableViewCellAccessoryCheckmark) {

                        oldCell.accessoryType = UITableViewCellAccessoryNone;
                    } 
                }



    NSString *pickedSound = [failSounds objectAtIndex:indexPath.row];
    NSLog(@"Picked sound is %@", pickedSound);
    [prefs setObject:pickedSound forKey:@"pickedFailSound"];
    [prefs synchronize];        

    [self performSelector:@selector(loadSound) withObject:nil];
    [failSound play];



    }

}

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You aren't remembering to reset the accessory type for dequeued cells.

This should fix it for you;

  cell.accessoryType = UITableViewCellAccessoryNone;

  if (indexPath.row == index) {
            cell.accessoryType = UITableViewCellAccessoryCheckmark;
  }

Handy tip : You may find it useful to use switch(indexPath.section) rather than lots of if ... elseif ... else constructs. Although you're OK now with just 2 sections, I find that using switch makes it easier to scale up the number of sections and also makes it mentally easier to read throught the code since you often have if .. else constructs used for other things - having the different syntax helps make it clearer what the tests are for.

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In - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPathafter each declaration of cell try reseting the cells accessoryType by adding following line: cell.accessoryType = UITableViewCellAccessoryNone;