From Xojo Documentation

Property (As Double )
aTextArea.LineSpacing = newDoubleValue
DoubleValue = aTextArea.LineSpacing

New in 2012r2

Supported for all project types and targets.

This controls the spacing between lines. So if you wanted your lines to be double spaced, you would enter a value of 2. The default value is 1, or single spaced.


On Linux, LineSpacing is not accurate if the TextArea has variable text sizes.