VB.NET: Readline from line until end

Question

I want to ask if there's a way to use "readline", that it reads from a certain line until the end of the file. I need it because the user can save values from the program to a text file. Later he has a possibility to call the values back to the main program( ex. he wants to edit the values)

Everything works fine, but I have a multiline textbox, and if the user press ENTER, then after saving its immpossible to get the data in the right possition. What I search, is a way to tell the program, to read from line 20 until the end of the file

My Text saving code

Private Sub Button12_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button12.Click
    Dim Saveb As New SaveFileDialog()
    Dim myStreamWriter As System.IO.StreamWriter
    Saveb.Filter = "Text [*.txt*]|*.txt|All Files [*.*]|*.*"
    Saveb.CheckPathExists = True
    Saveb.CreatePrompt = False
    Saveb.FileName = "b" & (TextBox1.Text)
    Saveb.Title = "Speichern"
    Saveb.ShowDialog(Me)
    Try
        myStreamWriter = System.IO.File.AppendText(Saveb.FileName)
        myStreamWriter.WriteLine(TextBox1.Text)
        myStreamWriter.WriteLine(TextBox13.Text & ".")
        myStreamWriter.WriteLine(TextBox14.Text & ".")
        myStreamWriter.WriteLine(ComboBox5.Text & ".")
        myStreamWriter.WriteLine(ComboBox6.Text & ".")
        myStreamWriter.WriteLine(TextBox4.Text & ".")
        myStreamWriter.WriteLine(SrNr.Text & ".")
        myStreamWriter.WriteLine(ComboBox4.Text & ".")
        myStreamWriter.WriteLine(ComboBox2.Text & ".")
        myStreamWriter.WriteLine(TextBox5.Text & ".")
        myStreamWriter.WriteLine(TextBox6.Text & ".")
        myStreamWriter.WriteLine(TextBox7.Text & ".")
        myStreamWriter.WriteLine(TextBox8.Text & ".")
        myStreamWriter.WriteLine(TextBox9.Text & ".")
        myStreamWriter.WriteLine(TextBox10.Text & ".")
        myStreamWriter.WriteLine(TextBox2.Text & ".")
        myStreamWriter.WriteLine(ComboBox1.Text & ".")
        myStreamWriter.WriteLine(TextBox14.Text & ".")
        myStreamWriter.WriteLine(TextBox11.Text & ".")
        myStreamWriter.WriteLine(ComboBox3.Text)
        myStreamWriter.WriteLine(TextBox12.Text & ".")

        myStreamWriter.Flush()
    Catch ex As Exception
    End Try
End Sub

And this is my reading code

 Private Sub Button13_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button13.Click
    Static count As Integer
    count = count + 1
    OpenFileDialog1.InitialDirectory = My.Computer.FileSystem.SpecialDirectories.MyDocuments
    OpenFileDialog1.Filter = "All Files (*.*)|*.*|Excel files (*.xlsx)|*.xlsx|CSV Files (*.csv)|*.csv|XLS Files (*.xls)|*xls"
    If (OpenFileDialog1.ShowDialog(Me) = System.Windows.Forms.DialogResult.OK) Then
        Dim read As IO.StreamReader
        read = IO.File.OpenText(OpenFileDialog1.FileName)
        TextBox17.Text = read.ReadToEnd()
        largetext.Text = read.ReadToEnd()
        read.Close()
        Dim readLines() As String = IO.File.ReadAllLines(OpenFileDialog1.FileName)
        TextBox1.Text = readLines(0)
        TextBox13.Text = readLines(1)
        TextBox14.Text = readLines(2)
        ComboBox5.Text = readLines(3)
        ComboBox6.Text = readLines(4)
        TextBox4.Text = readLines(5)
        SrNr.Text = readLines(6)
        ComboBox4.Text = readLines(7)
        ComboBox2.Text = readLines(8)
        TextBox5.Text = readLines(9)
        TextBox6.Text = readLines(10)
        TextBox7.Text = readLines(11)
        TextBox8.Text = readLines(12)
        TextBox9.Text = readLines(13)

        TextBox10.Text = readLines(14)
        TextBox2.Text = readLines(15)
        ComboBox1.Text = readLines(16)
        TextBox14.Text = readLines(17)
        TextBox11.Text = readLines(18)
        ComboBox3.Text = readLines(19)
        TextBox12.Text = readLines(20)
    End If
End Sub

The code gets into a hidden Textbox, from there it gets into the right place. I know its not professional, but Im newbie.

Answer 1

After setting all the first textboxes and combos, you should recreate the Lines collection of the TextBox12

If (OpenFileDialog1.ShowDialog(Me) = System.Windows.Forms.DialogResult.OK) Then
    Dim readLines() As String = IO.File.ReadAllLines(OpenFileDialog1.FileName)
    TextBox1.Text = readLines(0)
    .....
    TextBox12.Lines = readLines.Skip(20).ToArray
    ....

    TextBox17.Text = string.Join(Environment.NewLine, readLines)
    largetext.Text = TextBox17.Text

End If

Setting the Text property of the textboxes requires that you rebuild a single string using String.Join as showed in the last lines

Notice that the call to ReadAllLines remove the need to call anything else using a StreamReader, you have already all of your lines in memory and you could work directly with that readLines array