如何使用NON MVVM FASHION中的组填充ListView？

Question

在XAML中我有：

<ListView x:Name="ListView1" />

在代码背后我有：

Private Sub BuildList()
    For i As Integer = 1 To 5
        Dim a1 As New Border With {.Background = New SolidColorBrush(Windows.UI.Colors.DarkOrange), .Padding = New Thickness(5, 15, 5, 15), .Margin = New Thickness(0, 0, 0, 10)}
        Dim b1 As New TextBlock With {.Text = i, .FontSize = 30, .TextLineBounds = TextLineBounds.Tight}
        a1.Child = b1
        Dim c1 As New GroupItem With {.Content = a1}
        ListView1.Items.Add(c1)
        For j As Integer = 1 To 5
            Dim a2 As New Border With {.Background = New SolidColorBrush(Windows.UI.Colors.DarkOliveGreen), .Padding = New Thickness(20, 10, 0, 10), .Margin = New Thickness(0, 0, 0, 10)}
            Dim b2 As New TextBlock With {.Text = i, .FontSize = 20, .TextLineBounds = TextLineBounds.Tight}
            a2.Child = b2
            ListView1.Items.Add(a2)
        Next
    Next
    Debug.WriteLine(ListView1.IsGrouping.ToString)
End Sub

可悲的是，IsGrouping返回false并且标题不会像滚动时那样粘在顶部。

PS：请不要讲道如何绑定到CollectionViewsource。