XAML for QR scanner demo

QRScanner.xml

<Grid x:Name="LayoutRoot" Background="Transparent">
    <Rectangle x:Name="_previewRect" 
               Margin="0" 
               Height="800" 
               Width="600" 
               HorizontalAlignment="Center" 
               VerticalAlignment="Center">
        <Rectangle.Fill>
            <VideoBrush x:Name="_previewVideo">
                <VideoBrush.RelativeTransform>
                    <CompositeTransform  
                        x:Name="_previewTransform" CenterX=".5" CenterY=".5" />
                </VideoBrush.RelativeTransform>
            </VideoBrush>
        </Rectangle.Fill>
    </Rectangle>
    <ListBox Margin="10" x:Name="_matchesList" FontSize="30" FontWeight="ExtraBold" />
</Grid>