winform DataGridView 显示序号

 在发生任何单元格绘制之后，执行行级绘制时引发的事件

private void dataGridView1_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs e)
        {
            var dgv = sender as DataGridView;
            if (dgv != null)
            {
                Rectangle rect = new Rectangle(e.RowBounds.Location.X, e.RowBounds.Location.Y, dgv.RowHeadersWidth - 4, e.RowBounds.Height);
                TextRenderer.DrawText(e.Graphics, (e.RowIndex + 1).ToString(), dgv.RowHeadersDefaultCellStyle.Font, rect, dgv.RowHeadersDefaultCellStyle.ForeColor, TextFormatFlags.VerticalCenter | TextFormatFlags.Right);

            }
        }