How to make a list has a copy behavior while dragging an item from it.

[TruePluto]

I want to make a ListBox/ListView to store some Items as other ItemsControl's source or template.
When I drag item from it the source will not delete from the collection. MVVM style
The package default behavior is move and only the some the key to change the behavior. how can I make copy behavior as default.
Thank you.

[TruePluto]

Using the dd:DragDrop.DragDropCopyKeyState="LeftMouseButton" in the ItemsControl will make it with copy behavior
Mark.