Сохраните разделенные слова строк снова в исходном файле после редактирования

Imports System.IO
Imports System.Security
Imports Microsoft.CSharp

Imports Word = Microsoft.Office.Interop.Word


Public Class Form1
   
    Dim currentword As Integer = 0
    Dim Index1 As Integer = 0
    Dim Index2 As Integer = 0
    Dim line As String
    Dim opp As New OpenFileDialog


    Public Enum Direction
        Up = -1
        Down = 1

    End Enum

    Private Sub RichTextBox1_SelectionChanged(sender As Object, e As EventArgs) Handles DotPadTextBox.SelectionChanged
        Dim fci As Integer = DotPadTextBox.GetFirstCharIndexOfCurrentLine()

        currentline = DotPadTextBox.GetLineFromCharIndex(fci)

        Dim s As String = String.Format("Current line: {0}", currentline)
        Me.Text = s
        Me.BtnUp.Enabled = currentline >= 0

        Me.BtnDown.Enabled = currentline < DotPadTextBox.Lines.Count
    End Sub

    '***********CODE TO SPLIT ,RichTextBox2 LINE INTO WORD****************
    Private Sub DisplayWords(direction As Direction)
        Dim words As String() = Me.RichTextBox2.Lines.SelectMany(Function(line) line.Split(New String() {" "}, StringSplitOptions.RemoveEmptyEntries)).ToArray()
        Me.TxtCurrentWord.Text = words(currentword)
        Me.TxtPreviousWord.Text = If(currentword > 0, words(currentword - 1), Nothing)
        Me.TxtNextWord.Text = If(currentword < words.Count - 1, words(currentword + 1), Nothing)

        currentword += direction
        If currentword < 0 Then
            If currentword > words.Count - 1 Then
                currentword = words.Count - 1
            End If
        End If
    End Sub



    Private Sub BtnNextWord_Click(sender As Object, e As EventArgs) Handles BtnNextWord.Click
        DisplayWords(Direction.Down)
    End Sub

    Private Sub BtnPrevWord_Click(sender As Object, e As EventArgs) Handles BtnPrevWord.Click
        DisplayWords(Direction.Up)
    End Sub
    '***********CODE ENDS TO SPLIT ,RichTextBox2 LINE INTO WORD****************

    '************CODE TO OPEN FILE*****************
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click


        Try
            opp.Filter = "Document Files(*.doc)|*.doc|Document Files(*.docx)|*.docx|Text Files(*.txt)|*.txt|Rtf Files(*.rtf)|*.rtf|HTML Files(*.html)|*.html| AllFiles(*.*)|*.*"


            If opp.ShowDialog() = DialogResult.OK Then
                
                Dim SR As New IO.StreamReader(opp.FileName)
                DotPadTextBox.Text = SR.ReadToEnd()
                
            End If
            
        Catch ex As Exception
            Exit Sub
        End Try

    End Sub
    '************CODE ENDS TO OPEN FILE*****************

    '************CODE TO SAVE FILE*****************
    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        Dim saveMe As New SaveFileDialog()
        saveMe.Filter = "Text Documents(*.txt)|*.txt"
        If saveMe.ShowDialog() = Windows.Forms.DialogResult.OK Then
            RichTextBox2.SaveFile(saveMe.FileName, RichTextBoxStreamType.PlainText)
            File.WriteAllLines(saveMe.FileName, DotPadTextBox.Lines)
            MsgBox("File Saved as : " + saveMe.FileName)
        Else
            MsgBox("Failed to pick up file to save as")
        End If

    End Sub
    '************CODE END SAVE FILE*****************

End Class<pre>