From Xojo Documentation

Property (As Integer )
aListBox.ListIndex = newIntegerValue
IntegerValue = aListBox.ListIndex

Supported for all project types and targets.

The selected item number. The index is zero-based.


If no item is selected, ListIndex returns -1. If the ListBox is in multiple-row selection mode, then the number of the lowest selected row is returned. For example, if rows 1, 3, and 4 are selected, ListIndex returns 1.

You can put the ListBox into multiple-row selection mode by changing the SelectionType property.

Sample Code

The following code in the Change event handler displays the text in the first column of the selected row:

If Me.ListIndex >= 0 Then
MsgBox(Me.Cell(Me.ListIndex, 0))
End If