1、在dataGridView的RowPostPaint双击

 

2、吧这段代码写入

 　　 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);