How can I make text in a UILabel shrink font size

Question

If a UILabel contains too much text, how can I setup my label so that it shrinks font-sizes?

Here is how I am setting up my UILabel:

     descriptionLabel = [[UILabel alloc] initWithFrame:CGRectMake(200, 30, 130, 150)];
    [descriptionLabel setFont:[Utils getSystemFontWithSize:14]];
    [descriptionLabel setBackgroundColor:[UIColor clearColor]];
    [descriptionLabel setTextColor:[UIColor whiteColor]];
    descriptionLabel.numberOfLines = 1;
    [self addSubview:descriptionLabel];

Natika

Answer 1

descriptionLabel.adjustsFontSizeToFitWidth = YES;
descriptionLabel.minimumFontSize = 10.0; //adjust to preference obviously

The following example is tested and verified on iPhone Simulator 3.1.2:

UILabel *descriptionLabel = [[UILabel alloc] initWithFrame:CGRectMake(90, 0, 200, 30)];

descriptionLabel.font = [UIFont systemFontOfSize:14.0];
descriptionLabel.minimumFontSize = 10.0;
descriptionLabel.adjustsFontSizeToFitWidth = YES;
descriptionLabel.numberOfLines = 1;
descriptionLabel.text = @"supercalifragilisticexpialidocious even thought he sound of it is something quite attrocious";

Spake

I have added those line but it doesn't seem to work. Even when I specify my rect to be something small like CGRectMake(200,30,10,10) nothing happens. – Natika

I'm not sure what exactly your [Utils getSystemFontWithSize:] is returning… I'm editing my answer to include an example I've just tested and verified. – Spake

As of iOS 6, you should now be using setMinimumScaleFactor instead of minimumFontSize. – Carton

Thanks so much. That has just saved me so work and time. @Spake – Lancashire

Answer 2

To resize the text in a multi-line UILabel, you can use this helper method (based on code from 11 Pixel Studios):

+ (void)resizeFontForLabel:(UILabel*)aLabel maxSize:(int)maxSize minSize:(int)minSize { 
 // use font from provided label so we don't lose color, style, etc
 UIFont *font = aLabel.font;

 // start with maxSize and keep reducing until it doesn't clip
 for(int i = maxSize; i >= minSize; i--) {
  font = [font fontWithSize:i];
  CGSize constraintSize = CGSizeMake(aLabel.frame.size.width, MAXFLOAT);

  // This step checks how tall the label would be with the desired font.
  CGSize labelSize = [aLabel.text sizeWithFont:font constrainedToSize:constraintSize lineBreakMode:UILineBreakModeWordWrap];
  if(labelSize.height <= aLabel.frame.size.height)
   break;
 }
 // Set the UILabel's font to the newly adjusted font.
 aLabel.font = font;
}

Windowpane

In your for loop, the condition should be i >= minSize, not i > 10 – Bassarisk

Answer 3

Set the adjustsFontSizeToFitWidth property to YES.

Discipline

Answer 4

If you want the number of lines to also increase if needed, use Steve N's solution, with the if statement as so:

if(labelSize.height <= aLabel.frame.size.height)
{
  aLabel.numberOfLines = labelSize.height / font.lineHeight;

  break;
}

Fidellia

Or just set the number of lines to 0. – Artery