Untitled

How to make the StackPanel or DockPanel stretch to fit their containers in WPF?
<!-- Data template for ListBox -->
<DataTemplate DataType="{x:Type entities:Track}">
  <StackPanel Orientation="Vertical">
    <DockPanel>
      <TextBlock DockPanel.Dock="Left" Text="Now playing" />
      <TextBlock DockPanel.Dock="Right" Text="Time remaining" />
    </DockPanel>
    <TextBlock Text="{Binding Artist}" />
    <TextBlock Text="{Binding Title}" />
  </StackPanel>
</DataTemplate>

...

<ListBox
  Grid.Column="1"
  HorizontalAlignment="Stretch"
  VerticalAlignment="Stretch" />

<ListBox ...>
    <ListBox.ItemContainerStyle>
        <Style TargetType="ListBoxItem">
            <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
        </Style>
    </ListBox.ItemContainerStyle>