How to prevent an item being dropped into one TileList from another using Flex?

Question

I would like to prevent a user dragging certain items from one TileList to another. Whether or not they can be dropped into the TileList should be determined based on data associated with the item.

To show that the item cannot be dragged into the TileList I would like to show the normal white cross in red circle icon next to the cursor. If a drop is attempted when it has been determined that drop should not occur I would like to show an alert message explaining why this item could not be dropped.

Answer 1

This article should help you. The example in the article seems exactly what you want.

http://butterfliesandbugs.wordpress.com/2007/10/10/cancelling-a-drag-action-in-list-components/