uitableview first and last visible cell color change

Question

I'm trying to to implement this function in UITableView for iPhone: always have only the FIRST and LAST VISIBLE cell have a different background color, say red, while color of the other cells remain white. and a smooth change during scrolling.
I have tried:

in .m file:

NSIndexPath *firstRow;
UITableViewCell* firstCell;

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *simpleTableIdentifier = @"tableCell";    
    tableCell *cell = (tableCell *)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];

    if (cell == nil) 
    {
        NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"tableCell" owner:self options:nil];
        cell = [nib objectAtIndex:0];
    } 

    cell.nameLabel.text = [tableData objectAtIndex:indexPath.row];
    //cell.thumbnailImageView.image = image;

    return cell;
}

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath;
{
    NSArray *visible = [tableView indexPathsForVisibleRows];
    firstRow = (NSIndexPath *)[visible objectAtIndex:0];
    firstCell = [tableView cellForRowAtIndexPath:firstRow];
    firstCell.contentView.backgroundColor=[UIColor redColor];
    NSLog(@"main visible cell's row: %i", firstRow.row);
    [tableView endUpdates];
    firstCell.contentView.backgroundColor=[UIColor redColor];   
}

But the color wont update when scrolling back up.

Answer 1

You can do it all in cellForRowAtIndexPath if you want.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSString *tableViewCellID = @"cellID";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:tableViewCellID];
    if (!cell) 
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:tableViewCellID];

    [[cell textLabel] setText:[NSString stringWithFormat:@"some sting %i", [indexPath row]]];


    NSArray *visibleCells = [tableView visibleCells];

    for (int i = 0; i < [visibleCells count]; i++) {
        UITableViewCell *cell = [visibleCells objectAtIndex:i];
        if (i == 0 || i == [visibleCells count] - 1)
            [cell setBackgroundColor:[UIColor redColor]];
        else 
            [cell setBackgroundColor:[UIColor clearColor]];
    }

    return cell;
}

Answer 2

In your

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

Try something like this

//Find the first row
if(indexPath.row == 0){
    cell.contentView.backgroundColor = [UIColor redColor];
}

And to check for the last row, you should reuse the code you made for

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section