make master details relational in datagridview?

dear master,

Today I study one topic about make master details relational in datagridview and I did coding like this below

please suggest me about it, how to do correct coding

 SmartBrain_Professional.NorthwindEntities dbContext = new SmartBrain_Professional.NorthwindEntities();
            dbContext.Orders.LoadAsync().ContinueWith(loadTask =>
            {
                //Bind data to control when loading complete
                orderBindingSource.DataSource = dbContext.Orders.Include(Order => Order.Order_Details).ToArray();
            }, System.Threading.Tasks.TaskScheduler.FromCurrentSynchronizationContext());

I want like this picture below

best regards

adisone