Question

Is it not possible to remove several rows from UITableView while adding no new rows? I thought there was support for batch insertion and deletion but it appears that you can only adjust the table size by 1 item from the previous count.

When I attempt to remove a whole bunch of rows without adding anything new, I get the error:

Invalid update: invalid number of rows
in section 2. The number of rows
contained in an existing section
after the update (3) must be equal to
the number of rows contained in that
section before the update (0), plus or
minus the number of rows inserted or
deleted from that section (1 inserted,
0 deleted).’

This is how I’m doing the deletes:

// The section initially has 7 rows. I want to remove 5 of them.
// The underlying table store data has been cleared of the 5 rows
// content as of this point

int newRowCount = 5;
int aSection = 2;

// Create the index paths of the rows I want to delete

NSMutableArray *deletePaths = [NSMutableArray arrayWithCapacity:newRowCount];
for (int ix = 0; ix < newRowCount; ++ix)
{
    [deletePaths addObject:[NSIndexPath indexPathForRow:ix inSection:aSection]];                
}

// Start the updates
[aTableview beginUpdates];

if (deletePaths && [deletePaths count] > 0)
{
    [aTableview deleteRowsAtIndexPaths:deletePaths 
                      withRowAnimation:UITableViewRowAnimationNone];
}

[aTableview endUpdates];

Apple’s UITableView Documentation I’m following:
link text

Answer 1

A bit of a guess since I can’t see this part of the code, but make sure that

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

is returning the right number. It sounds like you’re deleting rows from a section without this method returning the new number of rows.