public async Task <IActionResult> Edit(int id, [Bind("ConferenceAndParticipantId,ParticipantId,ConferenceId")] ConferencesAndParticipant conferencesAndParticipant)
        {
            if (id != conferencesAndParticipant.ConferenceAndParticipantId)
            {
                return(NotFound());
            }

            if (ModelState.IsValid)
            {
                try
                {
                    _context.Update(conferencesAndParticipant);
                    await _context.SaveChangesAsync();
                }
                catch (DbUpdateConcurrencyException)
                {
                    if (!ConferencesAndParticipantExists(conferencesAndParticipant.ConferenceAndParticipantId))
                    {
                        return(NotFound());
                    }
                    else
                    {
                        throw;
                    }
                }
                return(RedirectToAction(nameof(Index)));
            }
            ViewData["ConferenceId"]  = new SelectList(_context.Conferences, "ConferenceId", "Aim", conferencesAndParticipant.ConferenceId);
            ViewData["ParticipantId"] = new SelectList(_context.Participants, "ParticipantId", "FullName", conferencesAndParticipant.ParticipantId);
            return(View(conferencesAndParticipant));
        }
        public async Task <IActionResult> Create([Bind("ConferenceAndParticipantId,ParticipantId,ConferenceId")] ConferencesAndParticipant conferencesAndParticipant)
        {
            if (ModelState.IsValid)
            {
                _context.Add(conferencesAndParticipant);
                await _context.SaveChangesAsync();

                return(RedirectToAction(nameof(Index)));
            }
            ViewData["ConferenceId"]  = new SelectList(_context.Conferences, "ConferenceId", "Aim", conferencesAndParticipant.ConferenceId);
            ViewData["ParticipantId"] = new SelectList(_context.Participants, "ParticipantId", "FullName", conferencesAndParticipant.ParticipantId);
            return(View(conferencesAndParticipant));
        }
        public async Task <IActionResult> Import(IFormFile fileExcel)
        {
            if (ModelState.IsValid)
            {
                if (fileExcel != null)
                {
                    using (var stream = new FileStream(fileExcel.FileName, FileMode.Create))
                    {
                        await fileExcel.CopyToAsync(stream);

                        using (XLWorkbook workBook = new XLWorkbook(stream, XLEventTracking.Disabled))
                        {
                            foreach (IXLWorksheet worksheet in workBook.Worksheets)
                            {
                                Location newloc;
                                var      l = (from loc in _context.Locations
                                              where loc.City.Contains(worksheet.Name)
                                              select loc).ToList();
                                if (l.Count() > 0)
                                {
                                    newloc = l[0];
                                }
                                else
                                {
                                    newloc          = new Location();
                                    newloc.City     = worksheet.Name;
                                    newloc.Country  = "можливо Україна";
                                    newloc.Capacity = 0;
                                    _context.Locations.Add(newloc);
                                }

                                foreach (IXLRow row in worksheet.RowsUsed())
                                {
                                    //try
                                    //{
                                    int        counter = 1;
                                    Conference conf    = new Conference();
                                    DateTime   date    = new DateTime(2020, 1, 1);
                                    conf.Title                       = row.Cell(1).Value.ToString();
                                    conf.FormId                      = Convert.ToInt32(row.Cell(2).Value);
                                    conf.OrganizerId                 = Convert.ToInt32(row.Cell(3).Value);
                                    conf.Aim                         = "невідомо";
                                    conf.Topic                       = "невідомо";
                                    conf.RequirementsForWorks        = "невідомо";
                                    conf.RequirementsForParticipants = "невідомо";
                                    conf.Price                       = 0;
                                    conf.DateAndTime                 = date;
                                    conf.Location                    = newloc;
                                    _context.Conferences.Add(conf);

                                    for (int i = 4; i <= 30; i++)
                                    {
                                        if (row.Cell(i).Value.ToString().Length > 0)
                                        {
                                            Participant participant;

                                            var p = (from par in _context.Participants
                                                     where par.FullName.Contains(row.Cell(i).Value.ToString())
                                                     select par).ToList();
                                            if (p.Count > 0)
                                            {
                                                participant = p[0];
                                            }
                                            else
                                            {
                                                participant          = new Participant();
                                                participant.FullName = row.Cell(i).Value.ToString();
                                                DateTime date1 = new DateTime(1980, 1, 1);
                                                participant.BirthDate   = date1;
                                                participant.Occupation  = "невідомо";
                                                participant.Institution = "невідомо";
                                                _context.Add(participant);
                                            }
                                            ConferencesAndParticipant cap = new ConferencesAndParticipant();
                                            cap.Conference  = conf;
                                            cap.Participant = participant;
                                            _context.ConferencesAndParticipants.Add(cap);
                                        }
                                    }
                                    //}
                                    //catch (Exception ex)
                                    //{ }
                                }
                            }
                        }
                    }
                }

                await _context.SaveChangesAsync();
            }
            return(RedirectToAction(nameof(Index)));
        }