vb.netのcsv出力

Public Sub SaveCsv(ByVal fp As String)
' CSVファイルオープン
Dim sw As IO.StreamWriter = _
New IO.StreamWriter(fp, False, _
System.Text.Encoding.GetEncoding("SHIFT-JIS"))
For r As Integer = 0 To Me.Rows.Count - 1
For c As Integer = 0 To Me.Columns.Count - 1
' DataGridViewのセルのデータ取得
Dim dt As String = ""
If Me.Rows(r).Cells(c).Value _
Is Nothing = False Then
dt = Me.Rows(r).Cells(c).Value.ToString()
End If
If c < Me.Columns.Count - 1 Then
dt = dt & ","
End If
' CSVファイル書込
sw.Write(dt)
Next
sw.Write(vbCrLf)
Next
' CSVファイルクローズ
sw.Close()
End Sub