Question

I have a tableView that needs to be updated after information has been inserted from another view. If I perform a

[self.tableView reloadData]; 

The very next time I insert more information in another view and try to reload the table, all the currently visible rows are duplicated.

In other words, when I start up the app I have:

tableView:     Row 1     Row 2 

Then I submit some information that will also show up in the table and suddenly I have:

tableView     Row 1     Row 2     Row 3 <- info I just added     Row 1     Row 2 

My numberOfRowsInSection implementation looks like this:

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {     return [ItemsController sharedItemsController].count; } 

My cellForRowAtIndexPath implementation looks like this:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {     ItemsController* controller = [ItemsController sharedItemsController];     NSMutableArray* recentItems = controller.listOfRecentItems;      CustomCell *cell = nil;     NSUInteger row = [indexPath row];      if( row < recentItems.count )     {         Items*  item = [recentItems objectAtIndex:row];         if( recentCellData == nil )             recentCellData = [[NSMutableDictionary alloc] initWithCapacity:[indexPath length]];          if( [recentCellData count] > 0 )             cell = [recentCellData objectForKey:[NSString stringWithFormat:@'%d', row]];         if (cell == nil) {             UIViewController * view1 = [[UIViewController alloc] initWithNibName:@'CustomCell' bundle:nil];              cell = (CustomCell*)[view1 view];              [recentCellData setObject:cell forKey:[NSString stringWithFormat:@'%d',row]];         }         // do some other stuff here     }     // Set up the cell     return cell; } 

What’s the best way to update the table and avoid duplicating the currently visible rows. Thank in advance for all the help!

Answer 1

The error isn’t in how you’re reloading the table, it’s in how you’re providing data to it. Set a breakpoint in the data source methods and the method that adds new rows to see where you’re going wrong.