DesktopButton.Underline

From Xojo Documentation

Property (As Boolean )
aDesktopButton.Underline = newBooleanValue
or
BooleanValue = aDesktopButton.Underline

New in 2021r3

Supported for all project types and targets.

If True, applies the underline style to the control’s caption and/or its text content if any.

Sample Code

This code underlines the control’s text or caption property.

Me.Underline = True

This code underlines the Caption property:

Me.Underline = True
Me.Caption = "underlined"