数据Excel从一列DataGridView到RichTextBox.text [VB.Net]

Question

我设法将我的数据从Excel传输到DataGridView。但是如何将数据从一列DataGridView传输到RichTextBox.Text？因为后来我想为Arduino添加代码Serial.Write(RichTextBox.Text)以便以后阅读。我无法找到解决方案，因为人们总是使用行DataGridView而不是列

这是我的完整代码：

Imports System.Data.OleDb

Public Class Form1

    Dim cn As New OleDbConnection
    Dim cm As New OleDbCommand
    Dim da As OleDbDataAdapter
    Dim dt As New DataTable

    Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing

        cn.Close()

    End Sub


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


        'OPEN CONNECTION TO Data Otak.xls
        cn.ConnectionString = "provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\Users\USER\Desktop\Aiszzy Electronics\Projects\Visual Basic\Excel to VB to Prosthetic Hands\Data Otak.xls;Extended Properties=Excel 8.0;"
        cn.Open()

        'Load file from Data Otak.xls into DataGridView1
        FillDataGridView("select * from [Sheet1$]")

    End Sub


    Private Sub FillDataGridView(ByVal Query As String)

        da = New OleDbDataAdapter(Query, cn)
        dt.Clear()
        da.Fill(dt)

        With DataGridView1
            .DataSource = dt
            .Columns(0).HeaderText = "No"
            .Columns(1).HeaderText = "Data 1"
            .Columns(2).HeaderText = "Data 2"
            .Columns(3).HeaderText = "Data 3"
            .Columns(1).AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
        End With

    End Sub



    Private Sub cb_COMPort_DropDown(ByVal sender As Object, ByVal e As System.EventArgs) Handles cb_COMPort.DropDown

        cb_COMPort.Items.Clear()

        For i As Integer = 0 To My.Computer.Ports.SerialPortNames.Count - 1

            cb_COMPort.Items.Add(My.Computer.Ports.SerialPortNames(i))

        Next

    End Sub



    Private Sub BtnConnect_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnConnect.Click


        If BtnConnect.Text = "Connect" Then

            If cb_COMPort.Text = "" Then
                MsgBox("Please Select COM Port")

            Else

                If SerialPort1.IsOpen Then
                    SerialPort1.Close()

                End If

                Try
                    SerialPort1.PortName = cb_COMPort.SelectedItem
                    SerialPort1.BaudRate = 9600
                    SerialPort1.Parity = IO.Ports.Parity.None
                    SerialPort1.StopBits = IO.Ports.StopBits.One
                    SerialPort1.DataBits = 8
                    SerialPort1.Open()

                    BtnConnect.Text = "Disconnect"

                    lbl_Connection.Text = "Status : COM Port Connected"
                    Timer1.Enabled = True
                    Button1.Enabled = True

                Catch ex As Exception
                    lbl_Connection.Text = "Status : COM Port Connection failed"
                    Timer1.Enabled = False

                    cn.Close()

                End Try

            End If
        Else
            BtnConnect.Text = "Connect"
            SerialPort1.Close()
            lbl_Connection.Text = "Status : COM Port Disconnected"
            Timer1.Enabled = False
            Button1.Enabled = False

            cn.Close()

        End If

    End Sub

End Class