Setting a WPF control to expand to fill available space, and no more

Question

How can I set up a WPF control to fill the available space in its parent's container, but not expand the parent?

The following snippet describes the layout I am attempting. I would like the Grid to stretch to accommodate the Expander, and I would like the ListBox only to fill the Grid. I want the ListBox's scroll bar to appear when the Grid is too small to show all the ListBoxItems.

<ScrollViewer>
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto" />
            <ColumnDefinition />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition />
        </Grid.RowDefinitions>
        <ListBox Grid.Row="0" Grid.Column="0" />
        <Expander Grid.Row="0" Grid.Column="1" Header="Expander" />
    </Grid>
</ScrollViewer>

Currently what happens is that the Grid stretches to fit the entire ListBox, and the outer ScrollViewer's vertical scroll bar appears. I only want the outer scroll bar to appear when the Expander gets too big to fit on screen.

Answer 1

What is the point of the ScrollViewer? Just let the ScrollViewer in the ListBox template appear naturally when too little room is available.

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto" />
        <ColumnDefinition />
    </Grid.ColumnDefinitions>
    <Grid.RowDefinitions>
        <RowDefinition />
    </Grid.RowDefinitions>
    <ListBox Grid.Row="0" Grid.Column="0" />
    <Expander Grid.Row="0" Grid.Column="1" Header="Expander" />
</Grid>

HTH, Kent