Question

I’m having a problem with my current App. It has one UITableView in the UIViewController. I have one UIButton at the bottom (out of the UITableView). It works in that way:

if ([[NSUserDefaults standardUserDefaults] boolForKey:@"bla"]) {
[[NSUserDefaults standardUserDefaults] setBool:FALSE forKey:@"bla"];
[tableView reloadData]; 
} else {

[[NSUserDefaults standardUserDefaults] setBool:TRUE forKey:@"tasks2do"];
[tableView reloadData]; }

This worked when I had the cell.textLabel.text Method in this way:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {    

static NSString *ident = @"indet";

cell = [tableView dequeueReusableCellWithIdentifier:ident];
if (cell == nil) {
    cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:ident] autorelease];

}

if (![[NSUserDefaults standardUserDefaults] boolForKey:@"bla"]) {

cell.textLabel.text = [firstArray objectAtIndex:indexPath.row]; 

} else {

cell.textLabel.text = [secondArray objectAtIndex:indexPath.row];

}                
return cell; }

Now I want to use an UILabel instead of cell.textLabel, because I need it for some reasons (eg. setting the labels frame)

For that I used the following code:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {    

static NSString *ident = @"indet";

cell = [tableView dequeueReusableCellWithIdentifier:ident];
if (cell == nil) {
    cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:ident] autorelease];
}
UILabel *thislabel = [[[UILabel alloc] initWithFrame:CGRectMake(10, 10, 250, 44)] autorelease];

if (![[NSUserDefaults standardUserDefaults] boolForKey:@"bla"]) {

    [thislabel setText:[firstArray objectAtIndex:indexPath.row]];

    } else {

    [thislabel setText:[secondArray objectAtIndex:indexPath.row]];

}   

[cell.contentView addSubview:thislabel];

return cell; }

That works fine, until I push the UIButton for switching. It switches, the cell shows the new text but behind the new text is still the old text as you can see here:

http://d.pr/Rqx2

(the firstArray contains the letter L, the secondArray contains the Letter J, it mixes up both up)

Do you have any idea for solving this problem since I tried some stuff (for example using 2 UILabels for the arrays and hide one)? Would be cool. 🙂

I hope my English is not too bad to understand, my English skills for writing aren’t the best, I’m sorry for that.

If you need further information / code just post it, shouldn’t be a problem.

Answer 1

I recommend you create a UITableViewCell subclass in which you configure the label (set frame and add it as subview in UITableViewCell’s initializer). Add a property for setting the text in the label and write a setter like this for the property:

- (void)setLabelText:(NSString *)newLabelText 
{
    if ([self.labelText isEqualToString:newLabelText]) return;
    [labelText autorelease];
    labelText = [newLabelText copy];

    self.label.text = labelText;
    [self.label setNeedsDisplay]; // or perhaps [self setNeedsDisplay];
}

Edit: by the way, the issue you’re dealing with is the caching. You recreate a new label every time a cell comes in view, even if the cell already had a label before. This happens because you initialize an UILabel outside the UITableViewCell initializer (which only should be called once for every cached cell, afterwards it can be retrieved from cache, including all it’s subviews).