如何接收命令的输出

Question

如何接收at命令的输出。

这是我的表格：

这是我的代码：

Imports System.Net

Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load, btnRefresh.Click
        PortList.Items.Clear()
        For Each a As String In My.Computer.Ports.SerialPortNames 
            'collecting available port
            PortList.Items.Add(a)
        Next
    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles btnConnect.Click
        If btnConnect.Text = "CONNECT" Then 'opeing port
            If SerialPort1.IsOpen Then
                SerialPort1.Close()
            End If
            Try
                With SerialPort1
                    .PortName = PortList.Text
                    .BaudRate = 115200
                    .ReadBufferSize = 500
                    .Parity = IO.Ports.Parity.None
                    .DataBits = 8
                    .StopBits = IO.Ports.StopBits.One
                    .Handshake = IO.Ports.Handshake.None
                End With
                SerialPort1.Open()
                btnConnect.Text = "DISCONNECT"
                PortList.Enabled = False
                With lblStatus
                    .Text = "Connected"
                    .ForeColor = Color.Green
                End With
            Catch ex As Exception
                MsgBox(ex.Message)
            End Try
        Else 'closing port
            Try
                SerialPort1.Close()
                btnConnect.Text = "CONNECT"
                PortList.Enabled = True
                With lblStatus
                    .Text = "Not Connected"
                    .ForeColor = Color.Red
                End With
            Catch ex As Exception
                MsgBox(ex.Message)
            End Try
        End If
    End Sub

    Private Sub Form1_FormClosed(sender As Object, e As FormClosedEventArgs) Handles MyBase.FormClosed
        Try
            SerialPort1.Close() 'closing serial port
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub

    Private Sub Button1_Click_1(sender As Object, e As EventArgs) Handles btnSend.Click
        If UssdInput.Text.Length < 1 Then Exit Sub
        Try
            SerialPort1.WriteLine("AT+CUSD=1," & Chr(34) & UssdInput.Text & Chr(34) & ",15" & vbCrLf) 'send at command
            UssdOutput.Text = SerialPort1.ReadExisting.ToString
        Catch ex As Exception
            MessageBox.Show(ex.Message, "ERROR", MessageBoxButtons.OK, 
            MessageBoxIcon.Error)
        End Try
        With UssdInput
            .SelectAll()
            .Focus()
        End With
    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs)
        MsgBox(System.Net.Dns.GetHostEntry(System.Net.Dns.GetHostName).AddressList(1).ToString())
    End Sub

    Private Sub UssdInput_KeyPress(sender As Object, e As KeyPressEventArgs) Handles UssdInput.KeyPress
        If e.KeyChar = vbCr Then
            btnSend.PerformClick()
        End If
    End Sub
End Class

Answer 1

您需要收听串口的DataReceived事件。这是一个例子：

Private Sub SerialPort1_DataReceivedHandler(sender As Object, e As SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
    Invoke(Sub() UssdOutput.Text &= SerialPort1.ReadExisting())
End Sub