Scrolling a ListView - screen height detection needed - xaml

Question

I am working on a WinRT app which contains a listview. The Listview has grown recently and I need to put a vertical scrollbar around it.
So far I have hardcoded the height in the Grid to 500.
However I want to know how to set the height to detect how much space is available. This may vary depending on the device being used. How do I do that?
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="500"/>
</Grid.RowDefinitions>
<StackPanel Grid.Row="0" Orientation="Horizontal">
<TextBlock Text="*" FontSize="40" FontWeight="Bold" Foreground="Red"/>
<TextBlock Text=" = Required " FontSize="20"/>
</StackPanel>
<ScrollViewer Grid.Row="1" VerticalScrollBarVisibility="Auto" >
<ListView
ItemsSource="{Binding Path=Survey.SelectedSection.Questions, Mode=TwoWay}"
IsSwipeEnabled="False"
SelectionMode="None"
Background="White"
ItemTemplateSelector="{StaticResource ResourceKey=QuestionDisplay}"
ItemContainerStyle=
"{StaticResource ResourceKey=QuestionListViewItemContainerStyle}" />
</ScrollViewer>
</Grid>

Answer 1

So like we discussed. ListView has a ScrollViewer alread embedded in its template. The reason it would invoke scrolling with a fixed height as opposed to naturally was a fixed boundary was provided to invoke it.
By adjusting your layout so that it's parent panel (and up the parent tree) didn't include StackPanel and using Grid instead with star * sizing it allowed a boundary to invoke it as desired. The reason for this is whereas StackPanel will only consume the space required, regardless of the space available. A Grid will consume whatever space is provided while restricting its children in its layout providing that boundary necessary to invoke the scrolling of the embedded ScrollViewer which has the attached property of ScrollViewer.VerticalScrollBarVisibility set to Auto by default.
Glad you found your fix, welcome to the wonderful world of XAML which once you get used to it, you'll generally find is a lot easier to work with than it's cousin HTML. Cheers :)