UILabel showing wrong Values in UITableView - objective-c

Question

I am using Coredata and NSFetchedResultsController to store and retrieve Values and show them in a table view.I am creating a custom label in cellForRowAtIndexPath and displaying the value of an attribute 'lastname'. But I am getting wrong values.
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
UILabel *label = nil;
if(cell == nil){
cell = [[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier]autorelease];
label = [[[UILabel alloc]initWithFrame:CGRectMake(160,10,120,21)]autorelease];
label.backgroundColor = [UIColor clearColor];
[cell.contentView addSubview:label];
//Configure the cell
List *list = [self.fetchedResultsController objectAtIndexPath:indexPath];
label.text = list.lastname;
}
[self configureCell:cell atIndexPath:indexPath];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
cell.selectionStyle = UITableViewCellSelectionStyleGray;
return cell;
}
the wierd part is that it is working fine if i remove the UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; line and the if condition.

Answer 1

You need to move
label.text = list.lastname;
outside of the
if(cell == nil)
The reason is, that the content inside of the if(cell == nil) will get called only x times, where x is the number of visible cells on the screen. As you scroll, the new cells are being reused and that's why they contain some incorrect value.
EDIT:
You will also need to move your
List *list = [self.fetchedResultsController objectAtIndexPath:indexPath];
outside of the if.
EDIT 2:
This is how it should look like:
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
UILabel *label = nil;
if(cell == nil){
cell = [[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier]autorelease];
label = [[[UILabel alloc]initWithFrame:CGRectMake(160,10,120,21)]autorelease];
label.backgroundColor = [UIColor clearColor];
label.tag=1;
[cell.contentView addSubview:label];
}
[self configureCell:cell atIndexPath:indexPath];
//Configure the cell
List *list = [self.fetchedResultsController objectAtIndexPath:indexPath];
label = (UILabel*)[cell.contentView viewWithTag:1];
label.text = list.lastname;
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
cell.selectionStyle = UITableViewCellSelectionStyleGray;
return cell;
}
this should work for you