DragDrop.PreviewQueryContinueDrag Attached Event
Occurs continuously while a drag-and-drop operation is in progress, and enables the drop source to end the drag-and-drop operation depending on the key/button states.
Assembly: PresentationCore (in PresentationCore.dll)
This event is raised continuously while the drag source is being dragged. For more information, see the QueryContinueDrag event.