Public Class Form1
 
    Dim dt As New cDataTableCSV
 
    Dim bs As New BindingSource
    Dim dgv As New DataGridView With {.Parent = Me, .DataSource = bs, .Top = _
      50, .Width = 464, .Height = 509}
 
    'Filter-Controls
    Dim txtNummer As New TextBox With {.Parent = Me, .Width = 90, .Left = 52, _
      .Top = 20}
    Dim txtLaenge As New TextBox With {.Parent = Me, .Width = 90, .Left = 152, _
    .Top = 20}
    Dim txtBreite As New TextBox With {.Parent = Me, .Width = 90, .Left = 252, _
    .Top = 20}
 
    Dim WithEvents btnFilter As New Button With {.Parent = Me, .Left = 8, .Top _
      = 20, .Width = 30, .Text = "Go"}
 
 
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) _
      Handles MyBase.Load
 
        Dim sAppPath As String
        sAppPath = Application.StartupPath
        Me.Size = New Size(480, 597)
 
        If Not dt.LoadFile(sAppPath & "\Seiten.csv", System.Text.Encoding.UTF7) _
          Then
            MsgBox("Datei konnte nicht geladen werden")
        Else
            dt.Columns(0).ColumnName = "Nummer"
            dt.Columns(1).ColumnName = "Laenge"
            dt.Columns(2).ColumnName = "Breite"
            dt.Columns(3).ColumnName = "Bezeichnung"
            bs.DataSource = dt
        End If
 
 
    End Sub
 
 
    Private Sub btnFilter_Click(sender As Object, _
        e As System.EventArgs) Handles btnFilter.Click
 
        Dim Laenge, Breite, Nummer As Decimal, filter As String = String.Empty
 
        bs.Filter = ""
 
        ' Teilenummer
        If Decimal.TryParse(txtNummer.Text, Nummer) Then
            filter = "Convert(Nummer, 'System.Decimal') = " & _
            Nummer.ToString(System.Globalization.CultureInfo.InvariantCulture)
        End If
 
        ' Länge
        If Decimal.TryParse(txtLaenge.Text, Laenge) Then
            filter = "Convert(Laenge, 'System.Decimal') = " & _
            Laenge.ToString(System.Globalization.CultureInfo.InvariantCulture)
        End If
 
        ' Breite
        If Decimal.TryParse(txtBreite.Text, Breite) Then
            'falls erste Bedingung gegeben --- Verknüpfung einschieben
            If Not filter = String.Empty Then filter &= " And "
 
            'zweite Bedingung setzen 
            filter &= "Convert(Breite, 'System.Decimal') = " & _
             Breite.ToString(System.Globalization.CultureInfo.InvariantCulture)
        End If
 
        'Filterstring zuweisen 
        bs.Filter = filter
 
    End Sub
 
 
End Class