public async Task <IActionResult> Create([Bind("Id,Num,Date,Sender,Recipient")] Invoice invoice, string[] markSparepartsInInvoice)
        {
            if (ModelState.IsValid)
            {
                _context.Add(invoice);
                await _context.SaveChangesAsync();

                foreach (var item in markSparepartsInInvoice)
                {
                    InvoiceSparepart invoiceSparepart = new InvoiceSparepart {
                        InvoiceId = _context.Invoices.LastOrDefault().Id, SparepartId = Int32.Parse(item)
                    };
                    _context.Add(invoiceSparepart);
                }
                await _context.SaveChangesAsync();

                return(RedirectToAction(nameof(Index)));
            }
            return(View(invoice));
        }
        public async Task <IActionResult> Edit(int id, [Bind("Id,Num,Date,Sender,Recipient")] Invoice invoice, string[] markSparepartsInInvoice)
        {
            if (id != invoice.Id)
            {
                return(NotFound());
            }

            if (ModelState.IsValid)
            {
                try
                {
                    _context.Update(invoice);
                    List <InvoiceSparepart> listForDell = _context.InvoiceSpareparts.Where(i => i.InvoiceId == id).ToList();
                    _context.InvoiceSpareparts.RemoveRange(listForDell);
                    await _context.SaveChangesAsync();

                    foreach (var item in markSparepartsInInvoice)
                    {
                        InvoiceSparepart invoiceSparepart = new InvoiceSparepart {
                            InvoiceId = id, SparepartId = Int32.Parse(item)
                        };
                        _context.Add(invoiceSparepart);
                    }
                    await _context.SaveChangesAsync();
                }
                catch (DbUpdateConcurrencyException)
                {
                    if (!InvoiceExists(invoice.Id))
                    {
                        return(NotFound());
                    }
                    else
                    {
                        throw;
                    }
                }
                return(RedirectToAction(nameof(Index)));
            }
            return(View(invoice));
        }