Question

Can someone explain me the following XAML line?

DataContext="{Binding RelativeSource={RelativeSource Self}}"

Here the simple example of use.

How to replace that line with a C# code?

Answer 1

That simply sets the DataContext property equal to the object with the property. The code equivalent would be this.DataContext = this;

Edit

The DataContext property is the object that is used as the context for all the bindings that occur on this object and its child objects. If you don’t have a DataContext correctly set to the model you want to bind to, all of your bindings will fail.

Edit2

Here is how to set it in code behind (matching your example):

public partial class ListViewTest : Window
{
    ObservableCollection<GameData> _GameCollection = 
        new ObservableCollection<GameData>();

    public ListViewTest()
    {
        _GameCollection.Add(new GameData { 
          GameName = "World Of Warcraft", 
          Creator = "Blizzard", 
          Publisher = "Blizzard" });
        _GameCollection.Add(new GameData { 
          GameName = "Halo", 
          Creator = "Bungie", 
          Publisher = "Microsoft" });
        _GameCollection.Add(new GameData { 
          GameName = "Gears Of War", 
          Creator = "Epic", 
          Publisher = "Microsoft" });

        InitializeComponent();

        this.DataContext = this;   //important part
    }

    public ObservableCollection<GameData> GameCollection
    { get { return _GameCollection; } }

    private void AddRow_Click(object sender, RoutedEventArgs e)
    {
      _GameCollection.Add(new GameData { 
          GameName = "A New Game", 
          Creator = "A New Creator", 
          Publisher = "A New Publisher" });
    }
}