最近又用了一下DataGridView控件，需要显示行号，我们知道在.net中DataGridView控件默认是不显示行号(数据的记录行数)的，后来通过查资料发现可以在DataGridView控件的RowPostPaint事件里面写代码就可以了，具体例子如下：

private void MaindataGridView_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs e)
        {
            Rectangle rectangle = new Rectangle(e.RowBounds.Location.X,
                e.RowBounds.Location.Y,
                MaindataGridView.RowHeadersWidth,
                e.RowBounds.Height);

TextRenderer.DrawText(e.Graphics, (e.RowIndex + 1).ToString(),
                MaindataGridView.RowHeadersDefaultCellStyle.Font,
                rectangle,
                MaindataGridView.RowHeadersDefaultCellStyle.ForeColor,
                TextFormatFlags.VerticalCenter | TextFormatFlags.Right);
        }