I defined some UserControl for ListBox

<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">

            <ListBox Height="Auto" HorizontalAlignment="Stretch" Name="deliveriesListBox" VerticalAlignment="Stretch" Width="Auto" DataContext="{Binding}" SelectionChanged="deliveriesListBoSelectionChanged">

                <ListBox.ItemTemplate>

                    <DataTemplate>

                        <Grid x:Name="LayoutRoot" xmlns:src="clr-namespace:App"  Margin="0,5">

                            <src:DItem />

                        </Grid>

                    </DataTemplate>    

                </ListBox.ItemTemplate>                    

            </ListBox>

        </Grid>

UserControl is

<UserControl x:Class="App.DItem"

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

    mc:Ignorable="d"

    FontFamily="{StaticResource PhoneFontFamilyNormal}"

    FontSize="{StaticResource PhoneFontSizeNormal}"

    Foreground="{StaticResource PhoneForegroundBrush}"

    d:DesignHeight="480" d:DesignWidth="480">

 

    <Grid x:Name="LayoutRoot" Margin="0,5">

        <Grid.RowDefinitions>

            <RowDefinition Height="Auto" />

            <RowDefinition Height="Auto" />

        </Grid.RowDefinitions>

        <Grid.ColumnDefinitions>

            <ColumnDefinition Width="*"/>

            <ColumnDefinition Width="Auto"/>

        </Grid.ColumnDefinitions>

 

        <TextBlock Grid.Row="0" Grid.Column="0" FontSize="42" HorizontalAlignment="Left"  Text="Hello" VerticalAlignment="Stretch" Margin="0" />

        <TextBlock Grid.Row="1" Grid.Column="1" FontSize="20" HorizontalAlignment="Right" TextAlignment="Right" Margin="0">

                                        <Run Text="OK" />

         </TextBlock>

        <TextBlock Grid.Row="1" Grid.Column="0" FontSize="20" Text="this is working only here.." HorizontalAlignment="Left"  />

    </Grid>

</UserControl>