I have tree view that displays Folders and grid view that displays Files, where the files resides in the folders. How can I allow drag and drop of the files into the folders, but this can only be done "behind the scene". Meaning, the files should not appear in the tree view, but only changing their (virtual) parent.

E.g.:
Parent
--> Child 1
--> Child 2

Child 1 has Files A and File B.
So if I drag File A to Child 2, I only want File A to disappear from Child 1 and appear on Child 2, on the grid. No files should appear on the tree view.

Can this be done? And how?