UILabel in Table View - the right way? - iphone

Question

I was trying to implement a UILabel into a cell and what I get is overlapping of some values when I scroll the table up and down a couple of times. I work with ARC so there is no release when I want, so my question is : What's the right way of implementing a Label into a tableView cell?
Here is how it looks
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
// Configure the cell...
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
cell.textLabel.textColor = [UIColor colorWithRed:0.6 green:0.6 blue:0.6 alpha:1];
cell.textLabel.highlightedTextColor = [UIColor colorWithRed:0.753 green:0.651 blue:0.1569 alpha:1];
UILabel *cellLabelS1 = [[UILabel alloc] initWithFrame:CGRectMake(250, 0, cell.frame.size.width, cell.frame.size.height)];
cellLabelS1.backgroundColor = [UIColor clearColor];
cellLabelS1.font = [UIFont boldSystemFontOfSize:16];
[cellLabelS1 setTextColor:[UIColor whiteColor]];
[cellLabelS1 setText:temperatureString];
temperatureString = nil;
[cell addSubview:cellLabelS1];
[[cell imageView]setImage:[UIImage imageNamed:imageFromCodeDay1]];
[[cell textLabel]setText:cityString];
return cell;
}

Answer 1

You should add a label to the cell only if you don't have one.If you reuse the cells on the second pass you add it again.
So my advice is to set a tag to the label and try to see if the cell contentView bass already the label. If not create and add it.
UILabel *myLabel = (UILabel *)[cell.contentView viewWithTag:2002];
if(!myLabel){
myLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 100, 22)];
myLabel.tag = 2002;
[cell.contentView addSubview:myLabel];
}
myLabel.text = #"my new text";

Answer 2

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
UILabel *cellLabelS1 = [[UILabel alloc] initWithFrame:CGRectMake(250, 0,cell.frame.size.width, cell.frame.size.height)];
cellLabelS1.backgroundColor = [UIColor clearColor];
cellLabelS1.tag = 200;
cellLabelS1.font = [UIFont boldSystemFontOfSize:16];
[cellLabelS1 setTextColor:[UIColor whiteColor]];
[cell addSubview:cellLabelS1];
}
// Configure the cell...
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
cell.textLabel.textColor = [UIColor colorWithRed:0.6 green:0.6 blue:0.6 alpha:1];
cell.textLabel.highlightedTextColor = [UIColor colorWithRed:0.753 green:0.651 blue:0.1569 alpha:1];
UILabel *cellLabelS1 = (UILabel*)[cell viewWithTag:200];
[cellLabelS1 setText:temperatureString];
temperatureString = nil;
[[cell imageView]setImage:[UIImage imageNamed:imageFromCodeDay1]];
[[cell textLabel]setText:cityString];
return cell;
}
may this will help you....

Answer 3

Your problem is in these lines:
UILabel *cellLabelS1 = [[UILabel alloc] initWithFrame:CGRectMake(250, 0, cell.frame.size.width, cell.frame.size.height)];
cellLabelS1.backgroundColor = [UIColor clearColor];
cellLabelS1.font = [UIFont boldSystemFontOfSize:16];
[cellLabelS1 setTextColor:[UIColor whiteColor]];
When you get a reused cell back from the table view, it already hass this label in it. What you can do to avoid adding duplicate labels is add it only if you need to allocate a new cell. However, this can make retrieving the label back from a reused cell quite complicated.
I would personally suggest creating a custom UITableViewCell in interface builder, and creating a custom UITableViewCell subclass that has a UILabel property.