Imports System.IO.Ports '使用SerialPort所引用的命名空间
Public Class Form1
Dim fx() As Byte ' 待发送数据数组
Dim Rc() As Byte ' 接收数据数组
' 数据定时接收与显示
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
Dim StrRc As String
Dim i As Integer
Dim n As Integer
n = SerialPort1.BytesToRead ' 读缓冲区数据量，有数据则接收
If n > 0 Then
ReDim Rc(n)
StrRc = ""
For i = 1 To n
Rc(i) = SerialPort1.ReadByte
StrRc = CStr(Hex(Rc(i))) & ""
Next
TextBox2.Text = StrRc
End If
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
ComboBox1.Items.Clear() '(清空列表)
ComboBox2.Items.Clear()
For Each portname As String In My.Computer.Ports.SerialPortNames
ComboBox1.Items.Add(portname) ' 显示所有串口
Try
SerialPort1.PortName = portname
SerialPort1.Open()
ComboBox2.Items.Add(portname) ' 显示可用串口
SerialPort1.Close()
Catch ex As Exception
MsgBox("可用串口检查 " & portname)
End Try
Next
If ComboBox1.Items.Count > 0 Then ComboBox1.SelectedIndex = 0
If ComboBox2.Items.Count > 0 Then
ComboBox2.SelectedIndex = 0
Button2.Enabled = True ' 有可用串口，可以打开操作
End If
End Sub
Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
If Button2.Text = "打开串口" Then
SerialPort1.PortName = ComboBox2.Text
If Not SerialPort1.IsOpen Then
SerialPort1.Open()
Button2.Text = "关闭串口"
Button3.Enabled = True '串口打开，可以发送数据
End If
Else
If SerialPort1.IsOpen Then SerialPort1.Close()
Button2.Text = " 打开串口"
Button3.Enabled = False
End If
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If Button1.Text = "打开串口" Then
SerialPort1.PortName = "COM1"
SerialPort1.Open() '(串口打开与关闭)
Button1.Text = "关闭串口"
Button2.Enabled = True
Timer1.Enabled = True
Else
If SerialPort1.IsOpen Then SerialPort1.Close()
Button1.Text = "打开串口"
Timer1.Enabled = False
Button2.Enabled = False
End If
End Sub
' 待发送数据处理与发送
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim i As Integer
Dim n As Integer
Dim Cmd As String = TextBox1.Text
n = Len(Cmd) \ 2
ReDim fx(n)
For i = 1 To n
fx(i) = CByte("&H" & Mid(Cmd, 2 * i - 1, 2))
Next
SerialPort1.Write(fx, 1, n) ' 发送数组fx第1到n数据
End Sub
End Class
以上代码在调试的时候出错，提示端口被占用。 好像是这一句出错 n = SerialPort1.BytesToRead
我刚学VB2005 大家帮我分析下原因吧