Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles Button1.Click
 
      Dim Filename As String = "c:\test\dgv.txt"
      Dim Separator As Char = ","c
      DGV_Export2File(dgvBericht, Filename, Separator)
   End Sub
 
   ''' <summary>
   ''' Inhalt eines Datagridview ausgeben in eine Textdatei
   ''' </summary>
   ''' <param name="DGV">das Datagridview</param>
   ''' <param name="FileName">Ausgabedatei</param>
   ''' <param name="Separator">Feldtrenner, z.Bsp Tab oder Komma</param>
   ''' <returns></returns>
   ''' <remarks></remarks>
   Public Function DGV_Export2File(ByVal DGV As DataGridView, ByVal FileName As _
     String, ByVal Separator As Char) As Boolean
 
      Try
         IO.File.Delete(FileName)
         Using SW As New IO.StreamWriter(FileName, False)
            'Header schreiben
            Using SW1 As New IO.StringWriter
               Dim s As String = Nothing
               For i As Integer = 0 To DGV.Columns.Count - 1
                  SW1.Write(DGV.Columns(i).HeaderText & Separator)
               Next
               s = SW1.ToString
               'Header ohne letzten Separator
               SW.WriteLine(s.Substring(0, s.Length - 1))
            End Using
 
            'Zeilenweise schreiben
            For i As Integer = 0 To DGV.Rows.Count - 1
               'New Row für Dateneingabe wird nicht geschrieben
               If Not DGV.Rows(i).IsNewRow Then
                  Using SW2 As New IO.StringWriter
                     Dim s As String = Nothing
                     For j As Integer = 0 To DGV.Columns.Count - 1
                        SW2.Write(DGV.Rows(i).Cells(j).Value.ToString & _
                          Separator)
                     Next
                     s = SW2.ToString
                     'Zeile ausgeben
                     SW.WriteLine(s.Substring(0, s.Length - 1))
                  End Using
               End If
            Next
         End Using
         Return True
      Catch ex As Exception
         MessageBox.Show(ex.ToString)
         Return False
      End Try
   End Function