ListBox: debugger available values

I am still trying to understand how drag and drop works with the ListBox control.

In the debugger, in the DropObject Event, I put a breakpoint and watched Obj As DragItem. The only entries I get are:

Destination
DragPicture
DropHeight
DropLeft
DropTop
DropWidth
FolderItem
Handle
MouseCursor
Picture
Text

Most of the time, Text is empty (holds nothing).

Also, where are the *Available entries ?

I am searching how can I make the difference from a Drag Row (from Me, from another ListBox), a Text Drop, etc. ?