DataGridView显示行号，设置行和列的颜色

 首先设置dataGridView的RowPostPaint事件，然后添加如下代码：

        private void dataGridView1_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs e)
        {
            // 在DataGridView中显示行号
            using (SolidBrush b = new SolidBrush(this.dataGridView1.RowHeadersDefaultCellStyle.ForeColor))
            {
                e.Graphics.DrawString(Convert.ToString(e.RowIndex + 1, System.Globalization.CultureInfo.CurrentUICulture), e.InheritedRowStyle.Font, b, e.RowBounds.Location.X + 20, e.RowBounds.Location.Y + 4);

            }
          
            DataGridViewRow dgr = dataGridView1.Rows[e.RowIndex];    

            if (dgr.Cells["x1"].Value?.ToString() == "")
             {
                dgr.DefaultCellStyle.BackColor = Color.Pink;//设置行颜色
             }

            if (dgr.Cells["x2"].Value.ToString() == "") 
            { 
                dgr.Cells["x2"].Style.BackColor = Color.Yellow;//设置列颜色
            }

        }