CODEWITHSUNDEEP
iosuitableviewreloaddata
Olie
Olie

Reputation: 24675

UITableView reload data works, but cells don't update on screen

I'm changing the text in a label within a UITableViewCell. I'm doing it in the main thread. I'm logging that I'm doing it to prove that my update is being called.

The update is not being reflected on-screen.

FWIW, I've done this dozens of times before and it has worked. I don't get what I might be doing differently this time.

I Googled for ideas. 99% of the answers are "make sure you dispatch to main thread" (I'm doing that), 3% are "make sure your tableview is wired up and your cellForIndexPath is being called" (that's done). The other 1.5% are miscellaneous horrid answers written by people guessing. ;)

Some code (the important bits are the last few lines. The rest is just setup):

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
   // blah blah snip.

   NSString * const cellID = NSStringFromClass([self class]);
   UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier: cellID];
   if (cell == nil)
   {
       cell = [[UITableViewCell alloc] initWithStyle: UITableViewCellStyleDefault reuseIdentifier: cellID];
       cell.backgroundColor = [UIColor clearColor];
   }

   // blah blah more snip

   // setup progress label
   // >>>Solution<<< (thanks @Dennis !) -- wrong label here.  Should be cellProgressTag
   UILabel *lProgress = (UILabel*) [cell viewWithTag: cellDescriptionTag];
   if (lProgress == nil)
   {
       float startX = 0;
       CGRect lRect = lTitle.frame;
       CGRect frame = CGRectMake(startX, (lRect.origin.y + lRect.size.height), (width - startX), 18);
       lProgress = [[UILabel alloc] initWithFrame: frame];
       lProgress.tag = cellProgressTag;
       UIFont *font = lProgress.font;
       lProgress.font = [font fontWithSize: 14];
       lProgress.textAlignment = NSTextAlignmentCenter;
       lProgress.textColor = textColor;
       [cell.contentView addSubview: lProgress];
   }

   // blah blah more snip

   // fill-out cell
   NSInteger row = [indexPath row];
   // blah blah more snip
   lProgress.text = [NSString stringWithFormat: @"current level: %d     %@", currentLevel, neededStr];
   if ([key isEqualToString: @"EE"])   NSLog(@"%s %@ lProgress: %@", __PRETTY_FUNCTION__, (([NSThread isMainThread]) ? @"(main thread)" : @"NOT MAIN THREAD"), lProgress); // DEBUG
   lDescr.text = [NSString stringWithFormat: @"%@%@", _descriptionPrefix, [oneTech objectForKey: @"description"]];

   return cell;
}

Sample log output:

2015-04-11 09:11:01.074 worfc[20202:5918312] -[myapp tableView:cellForRowAtIndexPath:] (main thread) lProgress: <UILabel: 0x815bd5f0; frame = (30 53; 320 30); text = 'current level: 0     74.1...'; userInteractionEnabled = NO; tag = 102; layer = <_UILabelLayer: 0x815bd6b0>>
2015-04-11 09:11:03.925 worfc[20202:5918312] -[myapp tableView:cellForRowAtIndexPath:] (main thread) lProgress: <UILabel: 0x815bd5f0; frame = (30 53; 320 30); text = 'current level: 0     76.6...'; userInteractionEnabled = NO; tag = 102; layer = <_UILabelLayer: 0x815bd6b0>>

Yet the lProgress label only ever updates if I hide & reshow the table (it's in a view controller I can pop up.) I'm trying to get the table to update live, as the result of a notification. (Yes, that's why I dispatch to main thread.)

Any hints?

Thanks!

Upvotes: 1

Views: 424

Answers (1)

Dennis
Dennis

Reputation: 2165

Not 100% sure if that is the issue, but the tags of the label do not match. You try to get it with cellProgressTag:

UILabel *lProgress = (UILabel*) [cell viewWithTag: cellDescriptionTag];

but when it is nil, you create the label and set tag cellProgressTag:

lProgress.tag = cellProgressTag;

That way, the next time you ask for the view with tag cellProgressTag you will get nil again.

Upvotes: 1

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