public void Save(Category category)
 {
     if (category.CategoryID == 0)
         context.Categories.Add(category);
     else
     {
         context.Entry(category).State = System.Data.EntityState.Modified;
     }
     context.SaveChanges();
 }
 public void Delete(Category category)
 {
     context.Categories.Remove(category);
     context.SaveChanges();
 }