Why can't I change the frame of my UILabel?

Robert Audi picture Robert Audi · Jul 6, 2013 · Viewed 16.2k times · Source

I have been trying for two days to modify the frame of a UILabel, which is ridiculous... The UILabel is an IBOutlet, but that is not the reason why it's not working: I tried to create a UILabel programatically and it still didn't work. Here is how I do it:

self.descriptionLabel.text = description;
self.descriptionLabel.lineBreakMode = NSLineBreakByWordWrapping;

CGSize textSize = [self.descriptionLabel.text sizeWithFont:[UIFont systemFontOfSize:12.0]
                                         constrainedToSize:CGSizeMake(self.descriptionLabel.frame.size.width, FLT_MAX)
                                             lineBreakMode:self.descriptionLabel.lineBreakMode];
CGFloat frameHeight = textSize.height;
CGRect frame = self.descriptionLabel.frame;
frame.size.height = frameHeight;
self.descriptionLabel.frame = frame;

CGRect bounds = self.descriptionLabel.frame;
bounds.origin.x = self.descriptionLabel.frame.origin.x + 10.0;
bounds.size.width = self.descriptionLabel.frame.size.width - 20.0;
self.descriptionLabel.bounds = bounds;
self.descriptionLabel.numberOfLines = 0;

I already asked on IRC and they told me that there is no reason why the frame would not be changed...

I also tried to create a frame with CGRectMake and give it arbitrary value but that didn't do the trick either..

Does anyone know what might be the problem please?

Edit 1: I logged the frame before and after, and I got odd results:

Before: 0.000000 0.000000 0.000000 0.000000
After: 0.000000 0.000000 0.000000 33525.000000

The height after I set the frame is the only value that makes sense (I have a lot of text in the label on purpose).

Edit 2: I changed the code as follows, the log says that the frame changed but on the simulator it didn't change; I proved it by adding red borders to the layer of the UILabel.

self.descriptionLabel.text = description;
self.descriptionLabel.lineBreakMode = NSLineBreakByWordWrapping;

CGSize textSize = [self.descriptionLabel.text sizeWithFont:[UIFont systemFontOfSize:12.0]
                                         constrainedToSize:CGSizeMake(self.view.frame.size.width, FLT_MAX)
                                             lineBreakMode:self.descriptionLabel.lineBreakMode];
CGFloat frameHeight = textSize.height;
CGRect frame = CGRectMake(0.0, 300.0, self.view.frame.size.width, frameHeight);
self.descriptionLabel.frame = frame;

DDLogInfo(@"After: %f %f %f %f", self.descriptionLabel.frame.origin.x, self.descriptionLabel.frame.origin.y, self.descriptionLabel.frame.size.width, self.descriptionLabel.frame.size.height);
// After: 0.000000 300.000000 320.000000 585.000000

self.descriptionLabel.numberOfLines = 0;
self.descriptionLabel.layer.borderColor = [UIColor redColor].CGColor;
self.descriptionLabel.layer.borderWidth = 2;

Proof

Answer

rdelmar picture rdelmar · Jul 6, 2013

If you're using auto layout, you shouldn't be doing any setting of frames -- either turn off auto layout, or use constraints to change the size of your label. The easiest way to do this is to give your label a height constraint (and width too, if you want a constant width) in IB, and make an IBOutlet to it. Then, in code, change the constant value of that constraint based on the value you get from sizeWithFont:constrainedToSize:lineBreakMode:.