From Xojo Documentation
New in 2019r2
A control that is a horizontal button made up of multiple, independent segments.
The easiest way to configure a SegmentedButton is to use the Segment Edit dialog in the IDE by clicking "Edit" in the Inspector. With it, you can create, delete, or reorder segments, label them, add an icon, and choose the selected segment or segments. (If the SelectionStyle is Multiple, you can have more than one selected segment.)
You set the behavior of the control with the SelectionStyle property. It enables you to choose whether the set of segments behaves as a group of radio buttons, a group of checkboxes, or a group of pushbutton. If it behaves like a group of checkboxes (Multiple), more than one can be selected at the same time. If it behaves like a pushbutton (None), then it is "selected" only while the mouse is held down.
If you want to do this work using code, you can address each segment with the Segment class. You instantiate an instance of this class for the segment that you want to address.
Resizing a Segmented Button
The individual segments do not automatically resize when the width of the SegmentedButton changes. You'll need to individually change the widths of each segment to to fit the new width of the control. This code (in the Resized event handler of a Window) resizes the segments to fit the new width of the SegmentedButton:
Const kPadding = 4
Var segWidth As Integer = (SegmentedButton1.Width / (SegmentedButton1.SegmentCount)) - kPadding
For i As Integer = 0 To SegmentedButton1.LastSegmentIndex
SegmentedButton1.SegmentAt(i).Width = segWidth
If you have placed an instance on a window, called SegmentedButton1, you can set or get the properties of any one segment with code like the following
When a segment is selected the Pressed event runs and is passed the index of the segment that was pressed:
// code for when segment 0 is selected
// code for when segment 1 is selected