SerialPort是用于串口通信的控件与VB6中的MSCOMM控件相似，使用很方便...

vb.net Code Imports System.IO.Ports Imports System.Text Public Class Form1     Dim RS232Com As New SerialPort     Dim mPortName As String     Public Sub OpenCOM()         mPortName = Me.CmbCom.SelectedItem.ToString         RS232Com = New SerialPort(mPortName, 9600, Parity.None, 8, StopBits.One)         RS232Com.Encoding = Encoding.ASCII         If Not RS232Com.IsOpen Then RS232Com.Open()     End Sub     Public Sub CloseCOM()         If RS232Com.IsOpen Then RS232Com.Close()     End Sub     Private Sub BtnOpen_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnOpen.Click         Call OpenCOM()     End Sub     Private Sub BtnClose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnClose.Click         Call CloseCOM()     End Sub     Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load         For Each sp As String In SerialPort.GetPortNames             Me.CmbCom.Items.Add(sp)         Next         Me.CmbCom.SelectedIndex = 0     End Sub     Private Sub BtnSend_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnSend.Click         RS232Com.Write(Me.TextBox1.Text) '即写命令过去     End Sub Private Sub BtnReceived_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnReceived.Click         Dim sOut As String         sOut = RS232Com.ReadExisting 'sOut即读到的字符串     End Sub End Class