// To protect from overposting attacks, enable the specific properties you want to bind to, for
        // more details, see https://aka.ms/RazorPagesCRUD.
        public async Task <IActionResult> OnPostAsync()
        {
            if (!ModelState.IsValid)
            {
                return(Page());
            }

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

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

            return(RedirectToPage("./Index"));
        }
        // To protect from overposting attacks, enable the specific properties you want to bind to, for
        // more details, see https://aka.ms/RazorPagesCRUD.
        public async Task <IActionResult> OnPostAsync()
        {
            if (!ModelState.IsValid)
            {
                return(Page());
            }
            foreach (var productcategory in _context.ProductCategories.ToList())
            {
                if (productcategory.ProductID == Product.Id)
                {
                    _context.Remove(productcategory);
                }
            }

            foreach (var id in ids)
            {
                var ProductandCategory = new ProductCategory()
                {
                    ProductID  = Product.Id,
                    CategoryID = id
                };
                _context.ProductCategories.Add(ProductandCategory);
            }
            _context.Attach(Product).State = EntityState.Modified;

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

            return(RedirectToPage("./Index"));
        }