How to launch the simplest code illustrating Master-Detail (compound List) object databinding in WPF?

Question

I am trying to run (in C# 4.0, Visual Studio 2010) the code from

• Unable to display a List as one of the columns of my view with ItemsControl and StackPanel?

Answer 1

The simpler answer:
This is funny but I do not see in HichemC's answer edits his penultimate edition of C# code working with the same XAML without any bloating by:

• ObservableCollection
• OnPropertyChanged()
• INotifyPropertyChanged
• PropertyChangedEventHandler

That this, simpler, code works for me:

public partial class MainWindow : Window
{
    public List myOrders { get; set; }
    Order order1 = new Order
    {
        OrderName = "Order1",
        PartsList = new List()
        {
              new Parts {PartName = "Part11", PartQuantity = 11},
              new Parts {PartName = "Part12", PartQuantity = 12}
         }
     };
    Order order2 = new Order
    {
        OrderName = "Order2",
        PartsList = new List()
        {
              new Parts {PartName = "Part21", PartQuantity = 21},
              new Parts {PartName = "Part22", PartQuantity = 22},
              new Parts {PartName = "Part23", PartQuantity = 23}
         }
     };

     public MainWindow()
        {
            InitializeComponent();
            myOrders = new List();
            myOrders.Add(order1);
            myOrders.Add(order2);
            DataContext = this;
        }
    }
    public class Order
    {
        public string OrderName { get; set; }
        public List PartsList { get; set; }
    }

    public class Parts
    {
        public string PartName { get; set; }
        public double PartQuantity { get; set; }
        }
}