Option Strict On : Option Explicit On : Option Infer Off
Public Class cDataTableCSV
    Inherits System.Data.DataTable
 
    Public Function LoadFile(ByVal filename As String, _
        ByVal textencoder As System.Text.Encoding, _
        Optional ByVal FeldTrennzeichen As Char = ";"c, _
        Optional ByVal ZeilenTrennzeichen As String = _
        Microsoft.VisualBasic.vbNewLine) As Boolean
 
        Me.Rows.Clear() : Me.Columns.Clear()
        Try
            'Zeilen lesen
            Dim lines() As String = _
            System.IO.File.ReadAllLines(filename, textencoder)
            'Maximale Feldzahl pro Zeile
            Dim fields() As String, maxfields As Integer = 0
            For i As Integer = 0 To lines.GetUpperBound(0)
                If lines(i) <> String.Empty Then
                    fields = lines(i).Split(FeldTrennzeichen)
                    maxfields = System.Math.Max(maxfields, fields.Length)
                End If
            Next i
            If maxfields < 1 Then Return False
 
            'Spalten für Felder erstellen
            For i As Integer = 0 To maxfields - 1
                Me.Columns.Add("SP_" + CStr(i), GetType(String))
                'Einige Standardeigenschaften der Spalten
                Me.Columns(i).AllowDBNull = True
                Me.Columns(i).DefaultValue = String.Empty
                Me.Columns(i).ReadOnly = False
            Next i
 
            'Datatable: Zeilen füllen
            Dim r As System.Data.DataRow
            For i As Integer = 0 To lines.GetUpperBound(0)
                If lines(i) <> String.Empty Then
                    fields = lines(i).Split(FeldTrennzeichen)
                    System.Array.Resize(fields, maxfields)
                    r = Me.NewRow
                    For k As Integer = 0 To maxfields - 1
                        If String.IsNullOrEmpty(fields(k)) Then
                            r(k) = String.Empty
                        Else
                            r(k) = fields(k).Trim
                        End If
                    Next k 'Felderschleife
                    Me.Rows.Add(r)
                End If
            Next i
            Return Me.Rows.Count > 0
        Catch ex As System.Exception
            Return False
        End Try
    End Function
 
    Public Function SaveFile _
    (ByVal Filename As String, ByVal Feldtrennzeichen As Char) As Boolean
        If Me.Rows.Count < 1 Then Return False
        Try
            Dim lines(Me.Rows.Count - 1) As String
            Dim fields(Me.Columns.Count - 1) As String
            For i As Integer = 0 To Me.Rows.Count - 1
                'Felder aus der Table zusammenstellen
                For k As Integer = 0 To Me.Columns.Count - 1
                    fields(k) = CType(Me.Rows(i).Item(k), String)
                Next k
                'Felder zusammenfügen
                lines(i) = System.String.Join(Feldtrennzeichen, fields)
                'Leere Spalten am Zeilenende entfernen
                While lines(i).EndsWith(Feldtrennzeichen)
                    lines(i) = lines(i).Substring(0, lines(i).Length - 1)
                End While
            Next i
            'Datei füllen
            System.IO.File.WriteAllLines(Filename, lines)
            Return True
        Catch ex As System.Exception
            Return False
        End Try
    End Function
 
    Public Sub AddColumn()
        Dim k As Integer = Me.Columns.Count
        Dim cn As String = "SP_" & CStr(k)
        Me.Columns.Add(cn, GetType(String))
        For i As Integer = 0 To Me.Rows.Count - 1
            Me.Rows(i).Item(k) = String.Empty
        Next i
    End Sub
End Class