DataGridView合并单元格

   #region"合并单元格（纵向合并及横向合并）"
        private int? nextrow = null;
        private int? nextcol = null;
        private void dataGridView1_CellFormatting(object sender, System.Windows.Forms.DataGridViewCellFormattingEventArgs e)
        {
            if (this.dataGridView1.Columns["description"].Index == e.ColumnIndex && e.RowIndex >= 0)
            {
                if (this.nextcol != null & e.ColumnIndex == this.nextcol)
                {
                    e.CellStyle.BackColor = Color.LightBlue;
                    this.nextcol = null;
                }
                if (this.nextrow != null & e.RowIndex == nextrow)
                {
                    e.CellStyle.BackColor = Color.LightPink;
                    this.nextrow = null;
                }
                if (e.RowIndex != this.dataGridView1.RowCount - 1)
                {
                    if (e.Value.ToString() == this.dataGridView1.Rows[e.RowIndex + 1].Cells[e.ColumnIndex].Value.ToString())
                    {
                        e.CellStyle.BackColor = Color.LightPink;
                        nextrow = e.RowIndex + 1;
                    }
                }

            }
            if (this.dataGridView1.Columns["name"].Index == e.ColumnIndex && e.RowIndex >= 0)
            {
                if (e.Value.ToString() == this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex + 1].Value.ToString())