I am currently trying to perform drag & drop on a X-control but the "drag enter" event is detected in the X-control and not in the event structure on the block diagram of the VI that contains the XCTL.
I am wondering if there are some limitations with the drag & drop events on this kind of controls.
I'm sorry but I had the confirm from people at NI France support that you can't trigger an event drag&drop on the whole XCTL.
You can only trigger this kind of event concerning individual controls inside the XCTL. It trigger the event structure in "facade.vi". from there if you can get a queue to communicate between the xctl and the containing VI, you can get your state machine doing the event you want (with a producer-consumer structure).
It's not perfect but it is the only workaround we found at Nerys.