public static ResponseViewModel<List<GetProductByCategory_Result>> GetProductByCategory(int id)
 {
     using (EcommerceEntities entities = new EcommerceEntities())
     {
         ResponseViewModel<List<GetProductByCategory_Result>> response = new ResponseViewModel<List<GetProductByCategory_Result>>();
         List<GetProductByCategory_Result> result = entities.GetProductByCategory(id).ToList();
         response.Data = result;
         return response;
     }
 }