Introduction - If you have any usage issues, please Google them yourself
The effect you would like to display to the user, usually indicating what would happen if a drop occurred at this point with the selected data. Typically, this is the value returned by the most recent call to CView::OnDragEnter or CView::OnDragOver. It can be one or more of the following:
* DROPEFFECT_NONE A drop would not be allowed.
* DROPEFFECT_COPY A copy operation would be performed.
* DROPEFFECT_MOVE A move operation would be performed.
* DROPEFFECT_LINK A link from the dropped data to the original data would be established.
* DROPEFFECT_SCROLL A drag scroll operation is about to occur or is occurring in the target.