VB .NET - Porta Serial

Public Class Form1

    Dim StrBufferOut As String

    Dim StrBufferIn As String

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        StrBufferOut = ""

        StrBufferIn = ""       

        btnConectar.Enabled = False

        btnEnviarDados.Enabled = False

        tmTimer.Enabled = False

    End Sub

    Private Sub btnConectar_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnConectar.Click

        If btnConectar.Text = "Conectar" Then

            btnConectar.Text = "Desconectar"

            btnEnviarDados.Enabled = True

            tmTimer.Enabled = True

            SerialPort.PortName = cmbPortasSeriais.Text

            SerialPort.Open()

        Else

            If btnConectar.Text = "Desconectar" Then

                btnConectar.Text = "Conectar"

                btnEnviarDados.Enabled = False

                tmTimer.Enabled = False

                SerialPort.Close()

            End If

        End If

    End Sub

    Private Sub btnDeterminarConexao_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDeterminarConexao.Click

        cmbPortasSeriais.Items.Clear()

        For Each ListaPortaSerial As String In My.Computer.Ports.SerialPortNames

            Me.cmbPortasSeriais.Items.Add(ListaPortaSerial)

        Next

        If cmbPortasSeriais.Items.Count > 0 Then

            cmbPortasSeriais.Text = cmbPortasSeriais.Items(0)

            btnConectar.Enabled = True

            MessageBox.Show("Selecione uma porta serial para se conectar.")

        Else

            btnConectar.Enabled = False

            btnEnviarDados.Enabled = False

            cmbPortasSeriais.Items.Clear()

            MessageBox.Show("Nâo foi encontrada nenhuma porta disponivel..")

        End If

    End Sub

    Private Sub btnEnviarDados_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnEnviarDados.Click

        SerialPort.DiscardOutBuffer()

        StrBufferOut = txtDiscardOutBuffer.Text

        SerialPort.Write(StrBufferOut)

    End Sub

    Private Sub tmTimer_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tmTimer.Tick

        StrBufferIn = SerialPort.ReadExisting

        If StrBufferIn <> "" Then

            StrBufferIn = StrBufferIn

            StrBufferIn = ""

            SerialPort.DiscardInBuffer()

        End If

    End Sub

End Class

Espero ter ajudado, até mais... Abraços!
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