UITableview sections overwrite in iPhone?

Question

I have one problem with two sections in UITableview grouped style. First section having 6 rows and second section having 3 rows. When i scroll the tableview up and down the last row content of section 2 is adding in first section first row and the first row content in first section is adding in last row of second section. I check my level best whether the cell become empty to load the content but, it is not happening while debugging. My code is ,

- (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];
            cell.backgroundColor = [UIColor whiteColor];

            if (indexPath.section == 0 && indexPath.row == 0) 
            {
                UILabel *Nameabel = [[UILabel alloc] initWithFrame:CGRectMake(5, 5, 140, 30)];
                Nameabel.text = @"Name";
                Nameabel.font = [UIFont fontWithName:@"Helvetica" size:15];
                Nameabel.backgroundColor = [UIColor clearColor];
                Nameabel.font = [UIFont boldSystemFontOfSize:15];
                [cell.contentView addSubview:Nameabel];

                textField = [[UITextField alloc] initWithFrame:CGRectMake(145, 5, 150, 30)];
                textField.placeholder = @"Student Name";
                textField.borderStyle = UITextBorderStyleNone;
                textField.font = [UIFont fontWithName:@"Helvetica" size:14];
                [cell.contentView addSubview:paymentCatTextField];

            }
            else if (indexPath.section == 1 && indexPath.row == 0) 
            {
                UILabel *RLabel = [[UILabel alloc] initWithFrame:CGRectMake(5, 5, 140, 30)];
                RLabel.text = @"Class";
                RLabel.backgroundColor = [UIColor clearColor];
                RLabel.font = [UIFont fontWithName:@"Helvetica" size:15];
                RLabel.font = [UIFont boldSystemFontOfSize:15];
                [cell.contentView RLabel];

                RTextField = [[UITextField alloc] initWithFrame:CGRectMake(145, 5, 150, 30)];
                RTextField.placeholder = @"class Name";
                RTextField.borderStyle = UITextBorderStyleNone;
                RTextField.keyboardType = UIKeyboardTypeNumbersAndPunctuation;
                RTextField.font = [UIFont fontWithName:@"Helvetica" size:14];
                [cell.contentView addSubview:RTextField];
            }
        }
       return cell;
    }

This is for sample. By this way the section 0 have 6 rows and section 1 have 3 rows. Where i am doing wrong. Please help my to solve this problem.

Thanks in advance.

Answer 1

Change your code to the following and try again:

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


    if (indexPath.section == 0 && indexPath.row == 0) {
         //bla bla
    } else if (indexPath.section == 1 && indexPath.row == 0) {
         //bla bla
    }

    return cell;
}

The reason is that you are setting the cell content only when you are not reusing the cell. That's wrong in most cases.

Answer 2

In addition to dasdom's answer I would also suggest removing the subviews before adding the labels.

if ([[cell.contentView subviews] count] > 0) {
    UIView *labelToClear = [[cell.contentView subviews] objectAtIndex:0];
    [labelToClear removeFromSuperview];
    UIView *textToClear = [[cell.contentView subviews] objectAtIndex:1];
    [textToClear removeFromSuperview];
}

and autoreleasing the subviews:

UILabel *Nameabel = [[[UILabel alloc] initWithFrame:CGRectMake(5, 5, 140, 30)] autorelease];
UITextField *textField = [[[UITextField alloc] initWithFrame:CGRectMake(145, 5, 150, 30)] autorelease];