Question

我有以下代码来监听和评估收到的字符串，但我现在需要添加在按钮点击时将预定义字符串发送回源代码的选项。

我非常感谢任何帮助或指示我需要研究的地方，我花了好几天努力完成这项工作，但收效甚微！

我正在得到的错误是button_click sub中的行opensock2 = New IO.StreamWriter(client.GetStream)没有连接，所以我想我需要从后台工作者传递连接，或者在表单加载时导致它但是我对如何做到这一点感到茫然。

所有人都非常感谢。

干杯，克里斯

Imports System.Net.Sockets
Imports System.Text

Public Class Form1
Private client As New System.Net.Sockets.TcpClient '("10.0.0.25", 4000)

Dim ipaddress(3) As Byte

Dim swon As String = "A55A6B0550000000FFFBDE0030C8" 'switch on
Dim swoff As String = "A55A6B0570000000FFFBDE0030E8" 'switch off
Dim but0 As String = "A55A6B0500000000FFFBDE002066" 'button release
Dim msg As String = "0000000000000000000000000000"
Dim t As Integer = "00"
Dim returndata As String = msg

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    Listener.RunWorkerAsync()
    Button2.Enabled = False
End Sub


Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles Listener.DoWork
    ipaddress(0) = 10
    ipaddress(1) = 0
    ipaddress(2) = 0
    ipaddress(3) = 14

    Dim opensock As New Net.Sockets.TcpListener(New Net.IPAddress(ipaddress), 4000)

    Try
        opensock.Start()
    Catch ex As System.Net.Sockets.SocketException
        mess.Text = "cannot start connection"
    End Try
    Dim tcpClient As TcpClient = opensock.AcceptTcpClient()

    While True
        If Listener.CancellationPending Then
            e.Cancel = True
            opensock.Stop()

            Exit While
        End If
        Listener.ReportProgress(1)
        Dim networkStream As NetworkStream = tcpClient.GetStream()
        If networkStream.CanWrite And networkStream.CanRead Then
            Listener.ReportProgress(2)
            Dim bytes(tcpClient.ReceiveBufferSize) As Byte
            Try

                networkStream.Read(bytes, 0, CInt(tcpClient.ReceiveBufferSize))
            Catch ex As Exception
                Listener.ReportProgress(3)

            End Try
            returndata = Encoding.ASCII.GetString(bytes)
            Listener.ReportProgress(4)

        Else
            'returndata = msg
        End If
    End While
End Sub


Private Sub Listener_RunWorkerCompleted(ByVal sender As System.Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles Listener.RunWorkerCompleted

    t = 40 - (40 * CInt("&H" & (returndata.Substring(12, 2))) / 255)
    temp.Text = t
    comm.Text = returndata
    If e.Cancelled Then
        mess.AppendText("cancelled" + vbCrLf)
    End If

End Sub

Private Sub Listener_ProgressChanged(ByVal sender As System.Object, ByVal e As System.ComponentModel.ProgressChangedEventArgs) Handles Listener.ProgressChanged
    Select Case e.ProgressPercentage
        Case 1
            mess.AppendText("connected" + vbCrLf)
            'comm.Text = msg
        Case 2
            mess.AppendText("Can read and write" + vbCrLf)
            mess.AppendText("data received" + vbCrLf)
        Case 3
            mess.AppendText("error" + vbCrLf)
        Case 4
            t = 40 - (40 * CInt("&H" & (returndata.Substring(12, 2))) / 255)
            temp.Text = t
            comm.Text = returndata
            mess.AppendText("Last temp" + vbCrLf)
    End Select

End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

    Dim opensock2 As IO.StreamWriter
    Try

        opensock2 = New IO.StreamWriter(client.GetStream)
        opensock2.WriteLine(swon)
        opensock2.WriteLine(but0)
        opensock2.Flush()
    Catch ex As Exception
        mess.AppendText(ex.ToString + vbCrLf)
    End Try

End Sub

End Class

将发送选项添加到vb.net侦听器

0 个答案: