In my app , I am returning 10 user objects in batches using NSNotificationCenter. When I get the 10 objects , I want to insert that data in table view. For this I am using following code

- (void)viewDidAppear:(BOOL)animated {

    recordCounter = 0;
    noOfRowsCounter = 0;

    // Some code
}

- (void) gotNotification: (NSNotification *) notification {

    NSMutableArray *tempArray = [[notification userInfo]valueForKey:KEY];

    NSLog(@"recordCounter BEFORE=> %d",recordCounter);
    NSLog(@"noOfRowsCounter BEFORE=> %d",noOfRowsCounter);

    self.insertIndexPaths = [[NSMutableArray alloc] init]; 
    for (User *user in tempArray) 
    {
        [self.contactsArray addObject:user];

        recordCounter++;
    }

    for (noOfRowsCounter = noOfRowsCounter; noOfRowsCounter < recordCounter; noOfRowsCounter++) {

        [self.insertIndexPaths addObject:[NSIndexPath indexPathForRow:recordCounter inSection:0]];

    }

    NSLog(@"recordCounter AFTER=> %d",recordCounter);
    NSLog(@"noOfRowsCounter AFTER=> %d",noOfRowsCounter);
    NSLog(@"self.insertIndexPaths count=> %d",[self.insertIndexPaths count]);
    [contactsTableView beginUpdates];
    [contactsTableView insertRowsAtIndexPaths:self.insertIndexPaths 
                             withRowAnimation:UITableViewRowAnimationNone];
    [contactsTableView endUpdates];

    [self.insertIndexPaths removeAllObjects];
}

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

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

    // I am doing this as I have 2 records in single row

    if ([self.insertIndexPaths count]%2 == 0) {

        NSLog(@"In IF::rows:: %d",[self.insertIndexPaths count]/2);
        return [self.insertIndexPaths count]/2;
    }
    else {
        NSLog(@"In ELSE::rows:: %d",[self.insertIndexPaths count]/2+1);
        return [self.insertIndexPaths count]/2 + 1;
    }
}

If I run my app I get the following errors & my app crashed. Here is my console log

    2012-04-04 12:15:36.559 AppName[1742:6803] recordCounter BEFORE=> 0
2012-04-04 12:15:36.563 AppName[1742:6803] noOfRowsCounter BEFORE=> 0
2012-04-04 12:15:38.539 AppName[1742:6803] recordCounter AFTER=> 10
2012-04-04 12:15:38.543 AppName[1742:6803] noOfRowsCounter AFTER=> 10
2012-04-04 12:15:38.546 AppName[1742:6803] self.insertIndexPaths count=> 10

2012-04-04 12:15:42.971 AppName[1742:6803] In IF::rows:: 5

2012-04-04 12:15:44.292 AppName[1742:6803] *** Assertion failure in -[UITableView _endCellAnimationsWithContext:], /SourceCache/UIKit/UIKit-1448.89/UITableView.m:995
2012-04-04 12:15:44.306 AppName[1742:6803] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0.  The number of rows contained in an existing section after the update (5) 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 (10 inserted, 0 deleted).'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x36c4164f __exceptionPreprocess + 114
    1   libobjc.A.dylib                     0x332fec5d objc_exception_throw + 24
    2   CoreFoundation                      0x36c41491 +[NSException raise:format:arguments:] + 68
    3   Foundation                          0x334ec573 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 62
    4   UIKit                               0x30ca4379 -[UITableView(_UITableViewPrivate) _endCellAnimationsWithContext:] + 4500
    5   UIKit                               0x30cae2f9 -[UITableView endUpdatesWithContext:] + 28
    6   UIKit                               0x30cae2d5 -[UITableView endUpdates] + 16
    7   AppName                       0x00004927 -[AppNameViewController batchNotification:] + 770
    8   Foundation                          0x334a4183 _nsnote_callback + 142
    9   CoreFoundation                      0x36c1020f __CFXNotificationPost_old + 402
    10  CoreFoundation                      0x36baaeeb _CFXNotificationPostNotification + 118
    11  Foundation                          0x334a15d3 -[NSNotificationCenter postNotificationName:object:userInfo:] + 70
    12  AppName                       0x00007705 -[AddressBook getAddressBookData] + 1700
    13  AppName                       0x0000447b -[AppNameViewController retriveAddressBookData] + 102
    14  Foundation                          0x334b3389 -[NSThread main] + 44
    15  Foundation                          0x335255cd __NSThread__main__ + 972
    16  libsystem_c.dylib                   0x350c0311 _pthread_start + 248
    17  libsystem_c.dylib                   0x350c1bbc start_wqthread + 0
)
terminate called after throwing an instance of 'NSException'

I want to add those records in table view . How can I do this. Thanks

UPDATE : Code of cellForRowAtIndexPath

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    ContactCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) 
    {
        NSArray *cellArray=[[NSBundle mainBundle] loadNibNamed:@"ContactCell" owner:self options:nil];
        //NSLog(@"cellArray count => %d",[cellArray count]);
        cell=[cellArray objectAtIndex:0];
    }

    // Configure the cell...

    // For showing 2 records in single row

    int row = indexPath.row * 2;
    if (row <= [self.contactsArray count]) 
    {
        User *user = [self.contactsArray objectAtIndex:row];
        NSLog(@"In ROW: %@",user.firstName);
        cell.firstNameLabel.text=[NSString stringWithFormat:@"%@",nameString];
    }

    if ((row + 1) < [self.contactsArray count]) 
    {

        User *user = [self.contactsArray objectAtIndex:row+1];
        NSLog(@"In ROW+1: %@",user.firstName);
        cell.secondNameLabel.text=[NSString stringWithFormat:@"%@",nameString];
    }

     return cell;
}

• iphone
• uitableview
• cell
• rows

according to your data you are returning 5 in number of rows in section but your self.insertIndexPaths is having 10 index paths

[contactsTableView insertRowsAtIndexPaths:self.insertIndexPaths 
                         withRowAnimation:UITableViewRowAnimationNone];

these lines specify to insert 10 rows,as mentioned clearly in the error in number of rows you get after updates should equal to the value returned in number of rows in section.

replace the lines

 for (noOfRowsCounter = noOfRowsCounter; noOfRowsCounter < recordCounter; noOfRowsCounter++) {

        [self.insertIndexPaths addObject:[NSIndexPath indexPathForRow:recordCounter inSection:0]];

    }

with

    int presentrows = [yourtablename numberOfRowsInSection:0];
    int Finalnumberofrows;
    if ([self.insertIndexPaths count]%2 == 0) {
    Finalnumberofrows = [self.contactsArray count]/2;
}
else {
    Finalnumberofrows = [self.contactsArray count]/2 + 1;
}
    for (presentrows; presentrows < Finalnumberofrows; presentrows++) {

    [self.insertIndexPaths addObject:[NSIndexPath indexPathForRow:presentrows inSection:0]];

}

and replace table view cell for row at index method - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

// I am doing this as I have 2 records in single row

if ([self.contactsArray count]%2 == 0) {

    NSLog(@"In IF::rows:: %d",[self.insertIndexPaths count]/2);
    return [self.contactsArray count]/2;
}
else {
    NSLog(@"In ELSE::rows:: %d",[self.insertIndexPaths count]/2+1);
    return [self.contactsArray count]/2 + 1;
}

}

The real error is listed after Terminating app due to uncaught exception.
It says: invalid number of rows in section 0. The number of rows contained in an existing section after the update (5) 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 (10 inserted, 0 deleted)

So, what's the problem? You had 0 rows, then inserted 10 and now say it has 5 ones? Doesn't make any sense. You should check your -tableView:numberOfRowsInSection: implementation.

I just see that you want to display two records in a single row. That makes no sense, really. It makes that table view animation just unnecessarily complicated.
However, if you'd want to stick with that you may not tell the table that you inserted 10 but 5 rows.

    [self.insertIndexPaths addObject:[NSIndexPath indexPathForRow:recordCounter inSection:0]];

}`
< - iOSAppDev 2012-04-04 10:02