DataGridView中实现自动编号

/// <summary>
/// DataGridView中实现自动编号
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void dataGridView1_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs e)
{
Rectangle rectangle = new Rectangle(e.RowBounds.Location.X,
e.RowBounds.Location.Y,
dataGridView1.RowHeadersWidth - 4,
e.RowBounds.Height);
TextRenderer.DrawText(e.Graphics,
(e.RowIndex + 1).ToString(),
dataGridView1.RowHeadersDefaultCellStyle.Font,
rectangle,
dataGridView1.RowHeadersDefaultCellStyle.ForeColor,
TextFormatFlags.VerticalCenter | TextFormatFlags.Right);
}