Treeview drop destination position: only INTO?

I have a treeview that I’m dragging files into from a desktop. When I
drag files onto the treeview, the cursor indicates that you can drop
things between the rows. Is there a way that I can turn off the option
to drop things between rows and only allow drops INTO my rows? I’m
worried mainly about the cursor’s visual feedback, not what happens in
my model later. Thanks for any help!