Why is tableviewcell not being updated?

- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
NSString *country=[[NSUserDefaults standardUserDefaults]objectForKey:@"namecountry"];
//url's
NSURL *url = [NSURL URLWithString:@"someurl"];
ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:url];
[request setPostValue:country forKey:@"c_name"];
[request setRequestMethod:@"POST"];
[request setValidatesSecureCertificate:NO];
[request setDelegate:self];
[request startSynchronous];

NSString *response = [request responseString];
NSLog(@"%@",response);
res=[[response componentsSeparatedByString:@","] retain];
NSLog(@"%@",[res objectAtIndex:18]);
show=[NSString stringWithFormat:@"%@",[res objectAtIndex:18]];
float f=[show floatValue];
show=[NSString stringWithFormat:@"%.2f %%",f];
[show retain];
}

This is the second tab that show the information.But when i click it it doesn't update sometimes it updates its random i guess.I want it to update every time.And please don't tell me to use [self.tableView reloadData]; When i click the tab bar icon i know it calls that method so no need to rewrite.This function is my viewDidAppear. Nslog log gives the updated value right so why it is not updating the table cell.

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = nil;
if (indexPath.row % 2 == 0) {
    // EVEN
    cell = [tableView dequeueReusableCellWithIdentifier:@"EvenCell"];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:@"EvenCell"] autorelease];
        UIView *bg = [[UIView alloc] initWithFrame:cell.frame];
        UIColor *colour = [[UIColor alloc] initWithRed: (208.0/255.f) green: (231.0/255.f) 
                                                  blue: (241.0/255.f) alpha: 1.0];
        bg.backgroundColor = colour; 
        cell.backgroundView = bg;
        cell.textLabel.backgroundColor = bg.backgroundColor;
        [bg release];
        cell.detailTextLabel.backgroundColor=[UIColor clearColor];
        cell.detailTextLabel.text=show;
    }
    cell.textLabel.text = [array objectAtIndex:indexPath.row];
    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;

} else {
    // ODD

    cell = [tableView dequeueReusableCellWithIdentifier:@"OddCell"];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:@"OddCell"] autorelease];
        UIView *bg = [[UIView alloc] initWithFrame:cell.frame];

        UIColor *colour = [[UIColor alloc] initWithRed: (143.0/255.f) green: (169.0/255.f) 
                                                  blue: (180.0/255.f) alpha: 1.0];
        bg.backgroundColor = colour;
        cell.backgroundView = bg;
        cell.textLabel.backgroundColor = bg.backgrou开发者_高级运维ndColor;
        [bg release];
    }
    cell.textLabel.text = [array objectAtIndex:indexPath.row];
    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;


 } 
 return cell;
}   

This one is the function that i create the cells i write cell.detailTextLabel.text=show; so it can show the updating value but as i said it is randomly update or not.Can anybody tell me where is the problem? btw i don't use the odd cell for now it is just concept.

---

There is no retain problem with this code, but if you are having problems with the cell refreshing here are things I would try if it were my code:

1. Confirm that cellForRowAtIndexPath is being called
2. NSLog() the results of [array objectAtIndex:indexPath.row] right before you assign it to the label and confirm that the value is the expected value.