Horizontally Positioning Controls inside ListBox - xaml

Question

I am making a UWP app and trying to place two TextBlock inside a ListBoxItem. HorizontalAlignment property doesn't seem to work.
I am trying to align the first TextBlock to the left and the second TextBlock to the right. Currently I am trying using Grids. Here's my XAML:
<Pivot.ItemTemplate>
<DataTemplate>
<ListBox ItemsSource="{Binding List}"
SelectionMode="Multiple"
ScrollViewer.HorizontalScrollMode="Disabled">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="9*"></ColumnDefinition>
<ColumnDefinition Width="1*"></ColumnDefinition>
</Grid.ColumnDefinitions>
<TextBlock Grid.Column="0"
Text="{Binding read}"
HorizontalAlignment="Left"
VerticalAlignment="Center"/>
<TextBlock Text="{Binding num}"
Grid.Column="1"/>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</DataTemplate>
</Pivot.ItemTemplate>

Answer 1

A couple of things you need to do here:
First, you need to stretch the alignment of the ListBoxItem, not the ListBox itself.
<ListBox>
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Setter Property="HorizontalContentAlignment" Value="Stretch" />
</Style>
</ListBox.ItemContainerStyle>
</ListBox>
Second, you should change Width="1*" to Width="Auto" otherwise the num TextBlock might get truncated. Then you can remove Width="9*" and add TextWrapping="Wrap" to the read TextBlock so if text will go to the next line if it's too long. You can safely remove HorizontalAlignment="Left" too.

Answer 2

Try to set the HorizontalContentAlignment property to stretch in the ListBox:
<ListBox ItemsSource="{Binding List}"
HorizontalContentAlignment="Stretch"
SelectionMode="Multiple"
ScrollViewer.HorizontalScrollMode="Disabled">
By default the HorizontalContentAlignment is set to left, and your listItem will not stretch to use all the available space, and that's why it's content will not be alligned properly to the right.