• https://www.exontrol.com/sg.jsp?content=support/faq/net/#dragdrop

Currently, the control supports only manual OLE Drag and Drop operations. See the OLEStartDrag and OLEDragDrop events for more details about implementing drag and drop operations into the control. Use the Background(exDragDropBefore) property to specify the visual appearance for the dragging items, before painting the items. Use the Background(exDragDropAfter) property to specify the visual appearance for the dragging items, after painting the items. Use the Background(exDragDropList) property to specify the graphic feedback for the item from the cursor, while the OLE drag and drop operation is running. If the HTMLPicture("OLEDragDropImage") property points to a valid picture object, it indicates the picture to be shown while the control performs OLE Drag and Drop operations. Currently, the  "OLEDragDropImage" has effect only for /COM version. In other words, you can specify a custom-sized picture rather than image of the dragging items, if you specify a picture with the name "OLEDragDropImage" ( no quotes included ).