public void Delete(Product products)
 {
     using (NorthWindContext context = new NorthWindContext())
     {
         var entity = context.Entry(products);
         entity.State = EntityState.Deleted;
         context.SaveChanges();
     }
 }
 public void Add(Product products)
 {
     using (NorthWindContext context = new NorthWindContext())
     {
         //context.Products.Add(products);
         var entity = context.Entry(products);
         entity.State = EntityState.Added;
         context.SaveChanges();
     }
 }