SetUnderline
Specifies that the contents of the run are displayed along with a line appearing directly below the character (less than all the spacing above and below the characters on the line).
Inherited from ApiTextPr.SetUnderline.
Example
Underline all default text with a single line in a document.
// How do I add an underline beneath the default paragraph text in a document?
// Emphasize body text by switching on the underline formatting option in a document.
let doc = Api.GetDocument();
let textPr = doc.GetDefaultTextPr();
textPr.SetUnderline(true);
let paragraph = doc.GetElement(0);
paragraph.AddText("A sample text underlined with a single line.");