exception while deleting a cell - iphone

Question

I have given 2 colours to my cell.
cell.contentView.backgroundColor = indexPath.row % 2 ? [UIColor whiteColor] : [UIColor blackColor] ;
Now, when i delete a row, say i deleted the cell that contains the colour black, then there will be 2 rows that contains the colour white. So i tried refreshing the row;
[self.tableView reloadRowsAtIndexPaths:[NSArray arrayWithObjects:indexPath, nil] withRowAnimation:YES];
This works, but when i delete all the records i get the following exception; Why is this ?
Assertion failure in -[UITableView _endCellAnimationsWithContext:], /SourceCache/UIKit_Sim/UIKit-1448.89/UITableView.m:961 and
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0. Attempt to delete more rows than exist in section.'
my code;
[self.tableView beginUpdates];
[self.myArray removeObjectsInArray:discardedItems ];
[self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObjects:indexPath, nil] withRowAnimation:YES];
[self.tableView reloadRowsAtIndexPaths:[NSArray arrayWithObjects:indexPath, nil] withRowAnimation:YES];
[self.tableView endUpdates];
How can i solve this ?

Answer 1

It thinks you have more rows than you do. Try something like this...
[self.tableView beginUpdates];
[self.myArray removeObjectsInArray:discardedItems ];
[self.tableView reloadData];
[self.tableView endUpdates];
Due to the nature of the tableview's data delegate, once you modify your data model the rest should follow.

Answer 2

Ok, let's think that you have 6 objects in your array, each one corresponding to the data-source for each cell. So, the delegate methods are called and you can actually edit the row and remove it, so you will end up now with 5 objects. What I always do and works like a charm is first re-sizing the array with the data-source and then updating the view.
//Remove the data
[self.myArray removeObjectsInArray:discardedItems ];
//Update the view
[self.tableView beginUpdates];
[self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObjects:indexPath, nil] withRowAnimation:YES];
[self.tableView endUpdates];
Unless you need to reload the data, meaning that some of the data-sources changed, you probably shouldn't be calling the update method. The exception was probably coming because you were trying to get info out of the sixth element of the array before you even finished updating the UITableView.
Hopefully this will work.