DataGridViewの行罫線に色を設定する方法

DataGridViewの行罫線に色を設定する方法
VB.NET

Private Sub dgv1_RowPostPaint(ByVal sender As Object, _
        ByVal e As DataGridViewRowPostPaintEventArgs) _
        Handles dgv1.RowPostPaint
    Dim dgv As DataGridView = CType(sender, DataGridView)
    Dim linePen As Pen
    Select Case e.RowIndex Mod 3
        Case 0
            linePen = Pens.Blue
        Case 1
            linePen = Pens.Green
        Case Else
            linePen = Pens.Red
    End Select
    Dim startX As Integer = IIf(dgv.RowHeadersVisible, dgv.RowHeadersWidth, 0)
    Dim startY As Integer = e.RowBounds.Top + e.RowBounds.Height - 1
    Dim endX As Integer = startX + _
        dgv.Columns.GetColumnsWidth(DataGridViewElementStates.Visible) - _
        dgv.HorizontalScrollingOffset
    e.Graphics.DrawLine(linePen, startX, startY, endX, startY)
End Sub

C#

private void dgv1_RowPostPaint(object sender,
    DataGridViewRowPostPaintEventArgs e)
{
    DataGridView dgv = (DataGridView)sender;
    Pen linePen;
    switch (e.RowIndex % 3)
    {
        case 0:
            linePen = Pens.Blue;
            break;
        case 1:
            linePen = Pens.Green;
            break;
        default:
            linePen = Pens.Red;
            break;
    }
    int startX = dgv.RowHeadersVisible ? dgv.RowHeadersWidth : 0;
    int startY = e.RowBounds.Top + e.RowBounds.Height - 1;
    int endX = startX + dgv.Columns.GetColumnsWidth(
        DataGridViewElementStates.Visible) -
        dgv.HorizontalScrollingOffset;
    e.Graphics.DrawLine(linePen,
        startX, startY, endX, startY);
}