From Xojo Documentation

This method uses a getter/setter (see Assigns) and acts like a property.

Property (As Integer )
aTextArea.VerticalScrollPosition = newIntegerValue
IntegerValue = aTextArea.VerticalScrollPosition

New in 2019r2

Supported for all project types and targets.

Use to get or set the topmost visible line (zero-based).


Use this property to determine the first visible line; set this property to scroll the control. Setting it to the last line or beyond the last line will simply move the vertical scrollbar's thumb to the bottom, not necessarily displaying the last line at the top of the control.