Conditional formatting not working with UITableView Cells - ios

Question

I'm thinking that this is an issue with reusing cells but I can't figure this out and would appreciate some additional eyes on it. I have a uitableviewcell subclass that compares two values, if one value is higher it changes the cell background to red, else it changes it to white. As I scroll, some cells are white that should be red and vice versa.
(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
tut_MaintListTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"maintCell" forIndexPath:indexPath];
// Configure the cell...
MaintItem *mItem = [self.fetchedResultsController objectAtIndexPath:indexPath];
[cell configureCellForEntry:mItem sendCar:self.carDetail];
return cell;
}
UITableViewCell Subclass
- (void)configureCellForEntry:(MaintItem *)mItem sendCar:(Car *)carDetails
{
self.itemLabel.text = [mItem valueForKey:#"item"];
self.actionLabel.text = [mItem valueForKey:#"action"];
self.engineLabel.text = [mItem valueForKey:#"engineCode"];
self.maintIDLabel.text = [[mItem valueForKey:#"maintID" ]stringValue];
// Grab the mileages recorded in the log for this maint item and turn it into a sorted array
NSArray *result = [[mItem.toLog valueForKey:#"mileage"] sortedArrayUsingDescriptors:[NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:#"" ascending:YES]]];
// Determine mileage of next service
NSString *nextServiceMileage = [NSString stringWithFormat:#"%d", [mItem.intMileage intValue] + [[result lastObject] intValue]];
nextServiceMileageNS = #([nextServiceMileage intValue]);
if ([mItem.frequencyID isEqualToNumber:[NSNumber numberWithInt:3]])
{
NSString *timing = [[NSString alloc] initWithFormat:#" %# Once at %# miles or %# months", [mItem valueForKeyPath:#"frequencyID"], [mItem valueForKeyPath:#"intMileage"], [mItem valueForKeyPath:#"intMonth"]];
NSString *howOften = [[NSString alloc] initWithFormat:#" %#", timing];
self.howOftenLabel.text = howOften;
if (carDetails.mileage > nextServiceMileageNS)
{
self.backgroundColor = [UIColor redColor];
}
else
{
self.backgroundColor = [UIColor whiteColor];
}
}
else if ([mItem.frequencyID isEqualToNumber:[NSNumber numberWithInt:4]])
{
NSString *timing = [[NSString alloc] initWithFormat:#" %# Every %# miles or %# months, due at %# ", [mItem valueForKeyPath:#"frequencyID"], [mItem valueForKeyPath:#"intMileage"], [mItem valueForKeyPath:#"intMonth"], nextServiceMileage];
NSString *howOften = [[NSString alloc] initWithFormat:#" %#", timing];
self.howOftenLabel.text = howOften;
if (carDetails.mileage > nextServiceMileageNS)
{
self.backgroundColor = [UIColor redColor];
}
else
{
self.backgroundColor = [UIColor whiteColor];
}
}
else
{
NSString *howOften = [[NSString alloc] initWithFormat:#" %#", [mItem valueForKeyPath:#"frequencyID"]];
self.howOftenLabel.text = howOften;
}
}

Answer 1

The Solution is: you have to set the backgroundColor in the else part too. Better solution would be,
UIView *backgroundView;
if (condition_1) {
backgroundView = [UIView new];
[backgroundView setBackgroundColor:[UIColor whiteColor]];
} else if (condition_2) {
backgroundView = [UIView new];
[backgroundView setBackgroundColor:[UIColor redColor]];
} else {
// here you can set or leave it.
}
[self setBackgroundView:backgroundView];
hope it will work for you...

Answer 2

The solution was that I was comparing two NSnumber objects in the if statement. I changed
if (carDetails.mileage > nextServiceMileageNS)to if ([carDetails.mileage intvalue] > [nextServiceMileageNS intvalue]) and now it worked correctly. The way the random background were applied it seemed to be a cell reuse issue.