串口读取超时视觉基本

Question

我需要读取串口来解析传入的字符串。如果我使用PuTTy我可以在串口中读取这些字符串，但如果我将VB应用程序与此代码一起使用，则它不起作用：

Private Sub comPortList_SelectedIndexChanged(sender As Object, e As EventArgs) Handles comPortList.SelectedIndexChanged
    Dim com1 As IO.Ports.SerialPort = Nothing
    Try
        com1 = My.Computer.Ports.OpenSerialPort(comPortList.SelectedItem, 9600)
        com1.ReadTimeout = 10000
        Do
            Dim Incoming As String = com1.ReadLine()
            If Incoming IsNot Nothing Then
                MsgBox(Incoming & vbCrLf)
            End If
        Loop
    Catch ex As TimeoutException
        MsgBox("Error: 'Serial Port read timed out.'") ' always getting this error
    Finally
        If com1 IsNot Nothing Then com1.Close()
    End Try
End Sub

我总是得到读取超时错误。此代码基于MSDN文档。

提前致谢。