Why my binding don't work on a ObservableCollection - wpf

Question

Hello I am trying to bind a ItemsSource to a ObservableCollection. It seems the ObservableCollection is not seen by the IntelliSense event if the ObservableCollection is public.
Do I have the declare something in XAML to make it visible ? Like in Window.Ressources.
My XAML code
<Window x:Class="ItemsContainer.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<StackPanel Orientation="Horizontal">
<ListBox ItemsSource="{Binding StringList}" />
</StackPanel> </Window>
My C# code
using System.Collections.ObjectModel;
using System.Windows;
namespace ItemsContainer
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
private ObservableCollection<string> stringList = new ObservableCollection<string>();
public ObservableCollection<string> StringList
{
get
{
return this.stringList;
}
set
{
this.stringList = value;
}
}
public MainWindow()
{
InitializeComponent();
this.stringList.Add("One");
this.stringList.Add("Two");
this.stringList.Add("Three");
this.stringList.Add("Four");
this.stringList.Add("Five");
this.stringList.Add("Six");
}
}
}
To the best of my knowledge that binding should bind to the property StringList of the current
DataContext, which is MainWindow.
Thanks for any pointer.
Edit:
This worked for me in XAML
<Window x:Class="ItemsContainer.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<StackPanel Orientation="Horizontal">
<ListBox ItemsSource="{Binding RelativeSource={RelativeSource AncestorType=Window},Path=StringList}" />
</StackPanel>
</Window>

Answer 1

The DataContext does not default to the MainWindow, you'd have to explicitly set that. Like so:
public MainWindow() {
InitializeComponent();
this.stringList.Add("One");
this.stringList.Add("Two");
this.stringList.Add("Three");
this.stringList.Add("Four");
this.stringList.Add("Five");
this.stringList.Add("Six");
this.DataContext = this;
}