public async Task <IActionResult> OnPostAsync()
        {
            if (!ModelState.IsValid)
            {
                return(Page());
            }

            _context.Attach(Winkel).State = EntityState.Modified;

            try
            {
                await _context.SaveChangesAsync();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!WinkelExists(Winkel.Id))
                {
                    return(NotFound());
                }
                else
                {
                    throw;
                }
            }

            return(RedirectToPage("./Index"));
        }
        public async Task <IActionResult> OnPostAsync(/*int kassaBonId*/)
        {
            if (!ModelState.IsValid)
            {
                return(Page());
            }

            _context.Attach(KassaBonItem).State = EntityState.Modified;

            try
            {
                await _context.SaveChangesAsync();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!KassaBonItemExists(KassaBonItem.Id))
                {
                    return(NotFound());
                }
                else
                {
                    throw;
                }
            }

            return(RedirectToPage("Details", new { @Id = KassaBonItem.KassaBonId }));
        }