SerialDataReceivedEventArgs无法正常工作

问题描述

我在这里有一个来自google的代码，它将显示文本消息到Richtextbox.但是，没有收到消息.

I have here a code from google that will show a text message to a richtextbox. But, there is no message received. 

这是代码:

Public Class Form1

    Dim spDrLine As String = ""
    Dim spBuffer As String = ""
    Dim receivedData As String = ""

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

    Private Sub spOpen()
        Try
            spClose()
            spObj.PortName = "COM6"
            spObj.BaudRate = 9600
            spObj.Parity = IO.Ports.Parity.None
            spObj.DataBits = 8
            spObj.StopBits = IO.Ports.StopBits.One
            spObj.Handshake = IO.Ports.Handshake.None
            spObj.DtrEnable = True  'imp
            spObj.RtsEnable = True 'imp
            spObj.NewLine = vbCr
            spObj.ReadTimeout = 250
            spObj.WriteTimeout = 250
            spObj.Open()
        Catch ex As Exception
            'handle the way you want
        End Try
    End Sub
    Private Sub spClose()
        Try
            If spObj.IsOpen Then
                spObj.Close()
                spObj.Dispose()
            End If
        Catch ex As Exception

        End Try
    End Sub

    Private Sub spObj_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles spObj.DataReceived
        Try
            If spObj.IsOpen Then
                spDrLine = spDrLine & spObj.ReadExisting() 'imp
                If InStr(1, spDrLine, vbCr) > 0 Or InStr(1, spDrLine, vbLf) > 0 Then
                    spBuffer = spDrLine
                    spDrLine = ""
                    Me.Invoke(New EventHandler(AddressOf doProcess)) 'imp
                Else
                    Exit Sub
                End If
            End If
        Catch ex As Exception

        End Try

    End Sub


    Function ReceiveSerialData() As String
        Try
            spDrLine = spDrLine & spObj.ReadExisting()

            If InStr(1, spDrLine, vbCr) > 0 Or InStr(1, spDrLine, vbLf) > 0 Then
                spBuffer = spDrLine
                spDrLine = ""
                Me.Invoke(New EventHandler(AddressOf doProcess)) 'imp
            Else
                Return spDrLine
            End If

            If spBuffer Is Nothing Then
                Return "nothing" & vbCrLf
            Else
                Return spBuffer
            End If

        Catch ex As TimeoutException
            Return "Error: Serial Port read timed out."
        End Try
    End Function

    Private Sub doProcess()
        'process spBuffer
        RichTextBox1.Text &= spBuffer
    End Sub

End Class

推荐答案

此论坛讨论的是Visual Studio WPF/SL设计器，Visual Studio指导自动化工具包，开发人员文档和帮助系统以及Visual Studio编辑器.

This forum is discussing Visual Studio WPF/SL Designer, Visual Studio Guidance Automation Toolkit, Developer Documentation and Help System, and Visual Studio Editor.

您的问题与VB开发有关，我将此线程移至相应的论坛以寻求专业解答.

Your issue is related to VB development I will move this thread to corresponding forum for a professional answer.

此致，

奥斯卡

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