Question

I am trying to create a table view which uses two types of cells – default and subtitle.

I tried to use a single reusable cell (*cell) which seemed to work fine until I got to the bottom cell which was off screen – when this came into view it was a duplicate of the first visible cell.

I thought that I could try to add a second type of cell (*cellB) and when I did it seemed to solve the problem however it would crash every so often with the following error:

Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'UITableView dataSource must return a cell from tableView:cellForRowAtIndexPath:'

I know that I am doing something wrong and I am pretty sure I am not implementing the reusable cells properly but after several days of frustration I would really appreciate some advice.

P.S. I have searched many previous posts but none seem to cover the issue of using two types of cells on the same table.

Thanks in advance.

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

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return  5; 
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{

 UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"UITableViewCell"];

 UITableViewCell *cellB = [tableView dequeueReusableCellWithIdentifier:@"UITableViewCellB"];


switch (indexPath.section) {


 case 0:
     if (cell == nil) {
         // The only subtitle cell
         cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle
                                      reuseIdentifier:@"UITableViewCell"]; 

     }

        [[cell textLabel] setText:title];
        [[cell textLabel] setTextColor:[UIColor whiteColor]]; 
        [[cell detailTextLabel] setText:[NSString stringWithFormat:@"Entry: £%@",price]];
        [[cell detailTextLabel] setTextColor:[UIColor colorWithWhite:1.0 alpha:.8]]; 


        cell.selectionStyle = UITableViewCellSelectionStyleNone; 

     break;

 case 1:
     if (cell == nil) {

         cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault
                                      reuseIdentifier:@"UITableViewCell"]; 

         UIView *cellBackView = [[UIView alloc] initWithFrame:CGRectZero];
         cellBackView.backgroundColor = [UIColor colorWithPatternImage: [UIImage imageNamed:@"PhotoFrame.png"]];
         cell.backgroundView = cellBackView;

     }

     [lImage setFrame:CGRectMake(0, 23, 320, 200)];

     [cell.contentView addSubview:lImage];

     break;

 case 2:
     if (cell == nil) {

         cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault
                                      reuseIdentifier:@"UITableViewCell"]; 

         UIView *cellBackView = [[UIView alloc] initWithFrame:CGRectZero];
         cellBackView.backgroundColor = [UIColor colorWithPatternImage: [UIImage imageNamed:@"PaperTop.png"]];
         cell.backgroundView = cellBackView;

     }

     break;

 case 3:
     if (cell == nil) {

         cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault
                                      reuseIdentifier:@"UITableViewCell"]; 


         UIView *cellBackView = [[UIView alloc] initWithFrame:CGRectZero];
         cellBackView.backgroundColor = [UIColor colorWithPatternImage: [UIImage imageNamed:@"Paper.png"]];
         cell.backgroundView = cellBackView;

     }

     break;

 case 4:
     // I'm pretty sure this bit is wrong but if I use (cell == nil) the first cell is shown instead
     if (cellB == nil) {

         cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault
                                      reuseIdentifier:@"UITableViewCellB"]; 

         UIView *cellBackView = [[UIView alloc] initWithFrame:CGRectZero];
         cellBackView.backgroundColor = [UIColor colorWithPatternImage: [UIImage imageNamed:@"PaperBottom.png"]];
         cell.backgroundView = cellBackView;

     }

     break;

 default:
     break;
} 

 return cell; 
}

Answer 1

As cgull pointed out, when [indexPath section] is 4, you’re initializing cellB, but still returning cell, which may or may not have a valid cell in it.

You need to have one variable that holds the cell you’re going to return, no matter the path taken through the switch:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{

    NSString identifier = @"UITableViewCell";
    if( [indexPath section] == 4 ){
        identifier = @"UITableViewCellB";
    }
    // Try to dequeue the appropriate cell kind
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier];


    switch (indexPath.section) {

            //other cases...

        case 4:
            // You now have only one variable that can possibly hold a cell.
            // If section is 4, it's either nil or a UITableViewCellB kind.
            if (cell == nil) {

                cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault
                                  reuseIdentifier:@"UITableViewCellB"];
                // Set up new cell

            }

            break;

        default:
            break;
    } 

    return cell; 
}