.NET How to use Barcode scanner ?

Code

<Window x:Class="MainWindow"

        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"

        xmlns:local="clr-namespace:hidtest"

        mc:Ignorable="d"

        Title="MainWindow" Height="350" Width="525" Loaded="Window_Loaded" WindowStartupLocation="CenterScreen" >

    <Grid>

        <StackPanel Margin="20" Width="300">

            <TextBlock Text="Barcode or magnetic card input: "/>

            <TextBox x:Name="BarcodeOrCardInput"  Height="20" KeyDown="BarcodeOrCardInput_KeyDown" LostKeyboardFocus="BarcodeOrCardInput_LostKeyboardFocus" />

            <Button x:Name="btnSubmit" Content="Submit" Margin="5" Click="btnSubmit_Click"/>

        </StackPanel>

    </Grid>

</Window>

Code

Class MainWindow

    Inherits Window



    Public Sub New()

        InitializeComponent()

    End Sub







    Private Sub BarcodeOrCardInput_KeyDown(sender As Object, e As KeyEventArgs)

        Dim key = CType(e.Key, System.Windows.Input.Key)

        e.Handled = Not (key >= System.Windows.Input.Key.D0 AndAlso key <= System.Windows.Input.Key.D9 OrElse key >= System.Windows.Input.Key.NumPad0 AndAlso key <= System.Windows.Input.Key.NumPad9 OrElse key = System.Windows.Input.Key.Back OrElse key = System.Windows.Input.Key.OemPeriod OrElse key = System.Windows.Input.Key.Decimal OrElse key = System.Windows.Input.Key.Tab OrElse key = System.Windows.Input.Key.F1 OrElse key = System.Windows.Input.Key.F2 OrElse key = System.Windows.Input.Key.F3 OrElse key = System.Windows.Input.Key.F4)



        If e.Key = Key.Enter Then

            Me.btnSubmit.[RaiseEvent](New RoutedEventArgs(Button.ClickEvent))

            BarcodeOrCardInput.Text = String.Empty

            Keyboard.Focus(BarcodeOrCardInput)

        End If

    End Sub



    Private Sub btnSubmit_Click(sender As Object, e As RoutedEventArgs)

        MessageBox.Show("record is saved in db")

    End Sub



    Private Sub BarcodeOrCardInput_LostKeyboardFocus(sender As Object, e As KeyboardFocusChangedEventArgs)

        Keyboard.Focus(BarcodeOrCardInput)

    End Sub



    Private Sub Window_Loaded(sender As Object, e As RoutedEventArgs)

        Keyboard.Focus(BarcodeOrCardInput)

    End Sub

End Class