Dim WithEvents SerialPort1 As SerialPort
    Dim Input As Byte
 
    Private Delegate Sub DelegateSub()
    Private Aktualisieren As New DelegateSub(AddressOf AktualisierenProc)
 
 
    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button4.Click
        SerialPort1 = New IO.Ports.SerialPort("COM1", 9600, Parity.None, 8, _
        StopBits.Two)
        With SerialPort1
            If .IsOpen Then .Close()
 
            .DtrEnable = False
            .RtsEnable = True
 
            .Open()
 
            Return
        End With
    End Sub
 
    Private Sub SP_DataRcv(ByVal sender As System.Object, ByVal e As _
      SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
        For i As Integer = 1 To SerialPort1.BytesToRead - 1
            Input = SerialPort1.ReadByte
            Me.Invoke(Aktualisieren)
        Next
    End Sub
 
    Private Sub AktualisierenProc()
        ListBox1.Items.Add(Input)
    End Sub