UITableViewCell ImageView not updating - ios

Question

I have a tableview in my app for messaging with custom tableviewcells. This tableview is populated with an array from JSON. I have a UIImageView in the cell that shows a blue dot image if the message is unread.
Here's some code:
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:YES];
messagesArray = [self getMessages];
[messagesTableView reloadData];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *cellIdentifier = #"MessagesCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (!cell)
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
NSDictionary *messagesDictionary = [messagesArray objectAtIndex:indexPath.row];
UILabel *nameLabel = (UILabel *)[cell viewWithTag:100];
nameLabel.text = [messagesDictionary objectForKey:#"fromUserName"];
UIImageView *readImage = (UIImageView *)[cell viewWithTag:103];
NSNumber *boolNumber = [messagesDictionary valueForKey:#"readFlag"];
BOOL read = [boolNumber boolValue];
if (!read)
readImage.image = [UIImage imageNamed:#"Message Read Circle"];
return cell;
}
When the message is selected, I send a message to the server to let it know that the message is read, but when I go back, it still has the unread image. If I quit the app in the simulator and reload the app, the unread image is gone from the message that I selected, so I know the mark as read message is going through. Why won't [messagesTableView reloadData] work?

Answer 1

Since table view cells are reused, you should set the image in any case,
and not only if read == NO. Something like:
if (read)
readImage.image = [UIImage imageNamed:#"Message Read Circle"];
else
readImage.image = [UIImage imageNamed:#"Message Unread Circle"];

Answer 2

It doesn't look like you are actually calling reloadData on your tableview in your viewDidAppear like you said you are doing.
Also, like Mike Z asked above, you may be having issues with timing of your getMessages call. Is this method synchronous, or asynchronous? Posting some of that code may help as well.
Also, you need to make sure that you set your readImage to nil if your message has been read. Remember, these cells are dequeued, so if you don't set the imageView for both the true and false state of the read property, you may get erroneous results.