cell labels are not refreshing in table - iphone

Question

I am attempting to call a reloadData on my table's rows on a viewDidAppear method access. However, my cells are not refreshing their values and I cannot figure out why, as it seems everything is being accessed in the order it is suppose to. To make matters more odd, 1 row actually does refresh, but none of the others do.
Here is my code...
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
// Set up the cell...
static NSString *CellWithIdentifier = #"Cell";
UITableViewCell *cell = (UITableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellWithIdentifier];
NSLog(#"generating cell contents");
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellWithIdentifier];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
cell.textLabel.text = [_tableGroup.options objectAtIndex:rowcount];
rowcount++;
//label for currently selected/saved setting
_currentSetting = [[UILabel alloc] initWithFrame:CGRectMake(160, 8, 115, 25)];
[_currentSetting setFont:[UIFont systemFontOfSize:14]];
_currentSetting.backgroundColor = [UIColor clearColor];
_currentSetting.textColor = [UIColor blueColor];
_currentSetting.textAlignment = NSTextAlignmentRight;
[cell.contentView addSubview:_currentSetting];
NSLog(#"added new label to cell");
}
//depending on the setting, set the label in the cell to what is currently selected
if (indexPath.section == 1 && indexPath.row == 0) {
_currentSetting.text = [NSString stringWithFormat:#"%# %#",[settings.mapDistance stringValue], NSLocalizedString(#"MILES_IDENTIFIER", nil)];
NSLog(#"setting map distance label: %#", settings.mapDistance);
}
else if(indexPath.section == 1 && indexPath.row == 1)
{
_currentSetting.text = [NSString stringWithFormat:#"%# %#",[settings.maxCustomers stringValue], NSLocalizedString(#"ITEMS_IDENTIFIER", nil)];
NSLog(#"setting max customers: %#", settings.maxCustomers);
}
else if(indexPath.section == 2)
{
_currentSetting.text = [NSString stringWithFormat:#"%# %#",[settings.maxProducts stringValue], NSLocalizedString(#"ITEMS_IDENTIFIER", nil)];
NSLog(#"setting max products: %#", settings.maxProducts);
}
return cell;
}
based on this code, i get this output with my NSLOGS.
this is the first run of the cells when the view is created. It generates 4 cells, puts labels in each cell, and in 3 of those labels, puts in a value.
generating cell contents
added new label to cell
generating cell contents
added new label to cell
setting map distance: 15
generating cell contents
added new label to cell
setting max customers: 250
generating cell contents
added new label to cell
setting max products: 150
at this point i have clicked a row, went to a different screen, and have now returned. as you can see, map distance is different. although no change is displayed, even though the code to change the label's text is accessed during the reload process.
reloading data
generating cell contents
generating cell contents
setting map distance: 25
generating cell contents
setting max customers: 250
generating cell contents
setting max products: 150
again, I'm at a loss because the last row DOES refresh correctly. But none of the others do.
Thanks

Answer 1

When you reload your tableView, the cells already exist and are dequeued from the tableView, so the condition if (cell == nil) returns false, and the cell creation code is not executed.
In that cell creation code, you are assigning a value to _currentSetting and then proceed with the acode assuming that value is correct. However, when the cell creation code is not executed, that value points to the latest created cell, and thus, it won't update.
To fix this: make _currentSetting a local variable and change the code to look like this:
(You don't really need to make it a local variable, but it's more appropriate because you don't really need a reference to the last label you created after you leave this method)
UILabel *_currentSetting = nil;
if (cell == nil) {
_currentSetting = ...
_currentSetting.tag = 123;
}
else
_currentSetting = [cell.contentView viewWithTag:123];
...

Answer 2

The problem here is that the second time (when you are reloading the view ) the _currentSetting is not having a valid memory .So it is better to implement a custom cell and do the job
Better refer this an excellent guide

Answer 3

The second time around, you can see that "added new label to cell" isn't being called, so you're re-using an old tableViewCell.
Note that you're not setting _currentSetting when re-using a cell, only when creating a new cell. So _currentSetting is set to the last new cell that was created, most likely the last cell in the table.
You need to make sure to set _currentSetting to the correct label (maybe by using viewWithTag: or something similar).
(e:f;b)