Question

I have an array with 20 objects. there can be more objects in that array. for simplicity reason lets say its only nsstring object in that array.

i want to show 3 of those elements in every row. so number of rows are

- (NSInteger) tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
 {
  int i = 0;

if ( ([myArray count] % 3) > 0 )
{
    i++;
}
return [myArray count] / 3 + i;

}

i have a helper veriable int lastObj=0

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

static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

if (cell == nil)
{
  ---instaniate the cell

   for (int i = 1; i <= 3; i++)
    {
        if (lastObj <= [myArray count])
        {
            --create cell content
            -- cellContent.myLabel.text=[myArray onbjectAtIndex:lastObj]
            --add cellContent to cell 
            lastObj++;

        }
    }
return cell;
}

so if i have 5 objects in that array, then they get displayed properly.
but if it the list has 14 elements then the first 9 elements gets display and it starts from element 0 and the rest dont show up. on the app you can see 3 rows and each have 3 elements of array.
so i’m trying to mimic 3 columns.

any idea how i can resolve this issue?

Answer 1

Try this:

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

    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil)
    {
      ---instaniate the cell
      cell = [[UITableViewCell alloc] init]; //If you don't ARC then retain accordingly. 

    }

       for (int i = indexPath.row * 3 ; i < indexPath.row * 3 + 3; i++)
        {


            if (i <= [myArray count])
            {

                --create cell content
                -- cellContent.myLabel.text=[myArray onbjectAtIndex:i]
                --add cellContent to cell 
                //forget about your last object helper. That would not work anyway. 

            }
        }
    return cell;
}

The Point is that cellForRowAtIndexPath is not nessessarily called in a certain sequence. It is rather coincidence that it is called for the first to seventh row from start. Theoretically it could be called in any sequence.
Think of this:
Your table has 30 rows. 10 of thes are visible at once.
At the beginning it is called for row 0 to 9. But understand that as a coincidence. It could be called in any sequence.
Then the user scrolls for 5 rows. The method is then called for cell 10 to 14. In this case the cells will be re-used. Your if (cell==nil) branch will not be entered.
Again in a row. Then the user crolls back 2 rows. Next calls of the method would be for row 9 and 8 – in that sequence.

So do never ever assume a certain sequence here, even if you seem to observe a certain sequence.