How to add line break for UILabel?

Question

Use \n as you are using in your string.

Set numberOfLines to 0 to allow for any number of lines.

label.numberOfLines = 0;

Update the label frame to match the size of the text using sizeWithFont:. If you don't do this your text will be vertically centered or cut off.

UILabel *label; // set frame to largest size you want
...
CGSize labelSize = [label.text sizeWithFont:label.font
                          constrainedToSize:label.frame.size
                              lineBreakMode:label.lineBreakMode];
label.frame = CGRectMake(
    label.frame.origin.x, label.frame.origin.y, 
    label.frame.size.width, labelSize.height);

Update : Replacement for deprecated

sizeWithFont:constrainedToSize:lineBreakMode:

Reference, Replacement for deprecated sizeWithFont: in iOS 7?

CGSize labelSize = [label.text sizeWithAttributes:@{NSFontAttributeName:label.font}];

label.frame = CGRectMake(
    label.frame.origin.x, label.frame.origin.y, 
    label.frame.size.width, labelSize.height);

Use option-return when typing in the little box in Interface Builder to insert a line feed (\n). In Interface Builder's Label attributes, set # Lines = 0.

Select the label and then change Lines property to 0 like in the above image, and then use \n in your string for line break.

In the interface builder, you can use Ctrl + Enter to insert /n to the position you want. This way could implement the following situation

aaa
aaaaaaa

If you read a string from an XML file, the line break \n in this string will not work in UILabel text. The \n is not parsed to a line break.

Here is a little trick to solve this issue:

// correct next line \n in string from XML file
NSString *myNewLineStr = @"\n";
myLabelText = [myLabelText stringByReplacingOccurrencesOfString:@"\\n" withString:myNewLineStr];

myLabel.text = myLabelText;

So you have to replace the unparsed \n part in your string by a parsed \n in a hardcoded NSString.

Here are my other label settings:

myLabel.numberOfLines = 0;
myLabel.backgroundColor = [UIColor lightGrayColor];
myLabel.textColor = [UIColor redColor]; 
myLabel.font = [UIFont fontWithName:@"Helvetica Neue" size:14.0];   
myLabel.textAlignment = UITextAlignmentCenter;

Most important is to set numberOfLines to 0 (= unlimited number of lines in label).

No idea why Apple has chosen to not parse \n in strings read from XML?

Hope this helps.

You have to set the numberOfLines property on the UILabel. The default is 1, if you set it to 0 it will remove all limits.