static extern void DisposeNavPreviewUPP(NavPreviewUPP userUPP);
static extern NavStatus NavCreateChooseFileDialog(ref NavDialogCreationOptions options, IntPtr inTypeList, NavEventUPP inEventProc, NavPreviewUPP inPreviewProc, NavObjectFilterUPP inFilterProc, ref IntPtr inClientData, out IntPtr navDialogRef);