自己在做WINFORM小玩意的時候需要在datagridview上顯示行號，上網搜索一下，找到如下代碼，不錯，先記錄下來了。
?? ?在RowPostPaint事件中畫出來

            // 繪制行號
        private void gvdata_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs e)
        {
            try
            {

                Rectangle rectangle = new Rectangle(e.RowBounds.Location.X,

                    Convert.ToInt32(e.RowBounds.Location.Y + (e.RowBounds.Height - gvdata.RowHeadersDefaultCellStyle.Font.Size) / 2),

                    gvdata.RowHeadersWidth - 4, e.RowBounds.Height);

                TextRenderer.DrawText(e.Graphics, (e.RowIndex + 1).ToString(),

                    gvdata.RowHeadersDefaultCellStyle.Font, rectangle, gvdata.RowHeadersDefaultCellStyle.ForeColor,

                    TextFormatFlags.Right);



            }

            catch (Exception ex)
            {

                Console.Write("dgv1_RowPostPaint：" + ex.Message);

            }
        }
  

效果如圖：

DataGridView添加行號