title: Binding a WPF DataGrid to a List<List<int>> object
body: <p>I try to <strong>bind a DataGrid in WPF</strong> to a <strong>list of lists</strong>.
  I am doing this:</p>
  
  <pre><code>private List&lt;List&lt;int&gt;&gt; _rows = new List&lt;List&lt;int&gt;&gt;();
  
  private void WindowLoaded(object sender, RoutedEventArgs e)
  {
        for (int i = 0; i &lt; 2; i++)
        {
             var row = new List&lt;int&gt;();
  
             for (int j = 0; j &lt; 2; j++)
             {
                 row.Add(j);
             }
  
             _rows.Add(row);
        }
  
        var dg1 = new DataGrid();
  
        for (int i = 0; i &lt; 2; i++)
        {
             var col = new DataGridTextColumn();
             col.Header = i.ToString();
             dg1.Columns.Add(col);
        }
  
        dg1.ItemsSource = _rows;
        this.LayoutRoot.Children.Add(dg1);
  }
  </code></pre>
  
  <p>When I run the program the DataGrid remains empty nothing works.
  <strong>how should I do to get this work?</strong></p>