Drop to AutoCAD, different behaviors

I'm struggling with a difference between drag-and-drop from Windows Shell -> AutoCAD and drag-and-drop from our app -> AutoCAD.

If one drops a dwg file from our app to AutoCAD => AutoCAD makes an "open" operation If one drops a dwg file from Desktop (for instance) to AutoCAD => AutoCAD makes an "insert" operation.

In both cases the path to the dwg file is correctly retrieved, the file is correctly read. "insert" means appending the content of the dropped file to the current AutoCAD drawing. "open" means closing the current AutoCAD drawing and opening the dropped file.

We did implement IDropSource开发者_C百科 using CF_HDROP (and DROPFILES) format, which works in a drag-and-drop from our application to Desktop, for instance.

Does anybody have a hint ?

Thank you.

In the DoDragDrop call, use the DROPEFFECT_LINK flag instead of the DROPEFFECT_COPY flag for the dwOKEffect parameter.