C# と VB.NET の質問掲示板

初心者さんこんにちは。
例えば，下のようにすると特定の「行」に罫線を引くことができます。
ただ，下の例は「動けばよい」という程度のもので，エラー処理などがありませんので，そのまま使ったりはしないでください。

    Private Sub DataGridView1_CellPainting(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellPaintingEventArgs) Handles DataGridView1.CellPainting
        If e.RowIndex > -1 And e.ColumnIndex > -1 Then
            Select Case Me.DataGridView1.Rows(e.RowIndex).Cells(0).Value
                Case "バナナ", "たまねぎ"
                    Using brush As New SolidBrush(e.CellStyle.BackColor)
                        e.Graphics.FillRectangle(brush, e.CellBounds)
                    End Using
                    Using pen As New Pen(Me.DataGridView1.GridColor)
                        With e.CellBounds
                            .Offset(-1, -1)
                            e.Graphics.DrawRectangle(pen, .Left, .Top, .Width, .Height)
                        End With
                    End Using
                    Using Pen As New Pen(Brushes.Black, 2)
                        With e.CellBounds
                            .Offset(-1, -1)
                            e.Graphics.DrawLine(Pen, .Left, .Bottom, .Right, .Bottom)
                        End With
                    End Using
                    If e.Value IsNot Nothing Then
                        Using brush As New SolidBrush(e.CellStyle.ForeColor)
                            Dim y As Integer = e.CellBounds.Y + (e.CellBounds.Height - e.Graphics.MeasureString(e.Value.ToString, e.CellStyle.Font).Height) / 2
                            e.Graphics.DrawString(e.Value.ToString, e.CellStyle.Font, brush, e.CellBounds.X, y, StringFormat.GenericDefault)
                        End Using
                    End If
                    e.Handled = True
            End Select
        End If
    End Sub