Private Sub myComPort_DataReceived(ByVal sender As Object, ByVal e As _
      System.IO.Ports.SerialDataReceivedEventArgs) Handles _
      myComPort.DataReceived
 
        Select Case e.EventType
            Case IO.Ports.SerialData.Chars
            Case IO.Ports.SerialData.Eof
        End Select
        Dim msg As String = Me.myComPort.ReadExisting
 
        ShowText(msg)
 
 
    End Sub
 
    Private Sub ShowText(ByVal text As String)
        If lblMeldungstext.InvokeRequired Then
            Dim d As New TextBoxCallback(AddressOf ShowText)
            Me.Invoke(d, New Object() {text})
        Else
            lblMeldungstext.Text = lbl.Meldungstext.Text & text
            End If
    End Sub

lblMeldungstext.Text = lblMeldungstext.Text & text

lblMeldungstext.Text = text

    Private Sub myComPort_DataReceived(ByVal sender As Object, ByVal e As _
      System.IO.Ports.SerialDataReceivedEventArgs) Handles _
      myComPort.DataReceived
 
        Select Case e.EventType
            Case IO.Ports.SerialData.Chars
            Case IO.Ports.SerialData.Eof
        End Select
        Dim msg As String = Me.myComPort.ReadExisting
 
        While (msg.Contains(Chr(0)))
            'die nachricht ist komplett
            Dim tmp = msg.Substring(0, msg.IndexOf(Chr(0)))
            ShowText(msg)
            msg = ""
        End While
        ShowText(msg)
 
 
    End Sub