public ActionResult Create(HttpPostedFileBase newImage, Product product, String submitButton)
        {
            switch (submitButton)
            {
                case "Add Picture":
                    AddPicture(newImage, product);
                    break;
                case "Create":
                    if (ModelState.IsValid)
                    {
                        product.EditedBy = product.CreatedBy = (Guid) Membership.GetUser().ProviderUserKey;
                        _db.Products.Add(product);
                        foreach (Image a in product.Images)
                        {
                            a.Product = product;
                            _db.Images.Add(a);
                        }
                        _db.SaveChanges();
                        return RedirectToAction("RedirectedBack", "Products");
                    }
                    break;
                default:
                    RemovePicture(product, submitButton);
                    break;
            }

            PrepareSelectLists();
            return View(product);
        }
        private static void AddPicture(HttpPostedFileBase newImage, Product product)
        {
            if (newImage != null)
            {
                String filePath = Guid.NewGuid() + Path.GetExtension(newImage.FileName);

                var newImg = new Image
                                 {
                                     ImageId = -1,
                                     Path = filePath
                                 };
                newImage.SaveAs(newImg.FullPath);
                product.Images.Add(newImg);
            }
        }
 private static void RemovePicture(Product product, string submitButton)
 {
     string path = submitButton.Substring(7); //remove "delete:"
     Image removedImage = product.Images.SingleOrDefault(img => img.Path == path);
     if (removedImage != null)
     {
         if (removedImage.ImageId < 1)
             System.IO.File.Delete(removedImage.FullPath);
         product.Images.Remove(removedImage);
     }
 }
        public ActionResult Edit(HttpPostedFileBase newImage, Product product, String submitButton)
        {
            switch (submitButton)
            {
                case "Add Picture":
                    AddPicture(newImage, product);
                    break;
                case "Save":
                    if (ModelState.IsValid)
                    {
                        product.EditedBy = (Guid) Membership.GetUser().ProviderUserKey;
                        ICollection<Image> newImages = product.Images.ToList();
                        Dictionary<String, Image> oldImages =
                            _db.Images.Where(img => img.ProductId == product.ProductId).ToDictionary(image => image.Path);
                        foreach (Image a in newImages)
                        {
                            if (oldImages.ContainsKey(a.Path))
                            {
                                oldImages.Remove(a.Path);
                                product.Images.Remove(a);
                            }
                            else
                            {
                                a.Product = product;
                                _db.Images.Add(a);
                            }
                        }
                        foreach (Image a in oldImages.Values)
                        {
                            System.IO.File.Delete(a.FullPath);
                            _db.Images.Remove(a);
                        }

                        _db.Entry(product).State = EntityState.Modified;
                        _db.SaveChanges();
                        return RedirectToAction("RedirectedBack", "Products");
                    }
                    break;
                default:
                    RemovePicture(product, submitButton);
                    break;
            }

            PrepareSelectLists(product.CategoryId, product.ProducerId);
            return View(product);
        }