C#datagridview 合并数据相同的行

　　private void dataGridView1_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
        {
            if (e.RowIndex >= 0 && e.ColumnIndex >= 0 && e.Value.ToString() != string.Empty)
            {
                //if (!string.IsNullOrEmpty(this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value.ToString()) && this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value != null)
                //{
                #region
                int UpRows = 0;//上面相同的行数
                int DownRows = 0;//下面相同的行数
                int count = 0;//总行数
                int cellwidth = e.CellBounds.Width;//列宽
                //获取下面的行数
                for (int i = e.RowIndex; i < this.dataGridView1.Rows.Count; i++)
                {
                    if (this.dataGridView1.Rows[i].Cells[e.ColumnIndex].Value.ToString().Equals(e.Value.ToString()))
                    {
                        DownRows++;
                    }
                    else
                    {
                        break;
                    }
                }
                //获取上面的行数
                for (int i = e.RowIndex; i >= 0; i--)
                {
                    if (this.dataGridView1.Rows[i].Cells[e.ColumnIndex].Value.ToString().Equals(e.Value.ToString()))
                    {
                        UpRows++;
                    }
                    else
                    {
                        break;
                    }
                }

                count = UpRows + DownRows - 1;//总行数
                //if (count < 2)
                //{ return; }
                using (Brush gridBrush = new SolidBrush(this.dataGridView1.GridColor), backColorBrush = new SolidBrush(e.CellStyle.BackColor))
                {
                    using (Pen gridLinePen = new Pen(gridBrush))
                    {
                        //this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value = this.dataGridView1.Rows[e.RowIndex - 1].Cells[e.ColumnIndex].Value;
                        //this.dataGridView1.Rows[e.RowIndex - 1].Cells[e.ColumnIndex].Value = DBNull.Value;
                        //清除单元格
                        e.Graphics.FillRectangle(backColorBrush, e.CellBounds);


                        if (e.Value != null)
                        {
                            int cellheight = e.CellBounds.Height;
                            SizeF size = e.Graphics.MeasureString(e.Value.ToString(), e.CellStyle.Font);
                            //if (e.RowIndex > 0 && this.dataGridView1.Rows[e.RowIndex - 1].Cells[e.ColumnIndex].Value.ToString() == e.Value.ToString())
                            //{

                            //}
                            //else
                            //{
                            e.Graphics.DrawString((e.Value).ToString(), e.CellStyle.Font, Brushes.Black, e.CellBounds.X + (cellwidth - size.Width) / 2, e.CellBounds.Y - cellheight * (UpRows - 1) + (cellheight * count - size.Height) / 2, StringFormat.GenericDefault);
                            //}
                        }

                        //如果下一行数据不等于当前行数据，则画当前单元格底边线
                        if (e.RowIndex < this.dataGridView1.Rows.Count - 1 && this.dataGridView1.Rows[e.RowIndex + 1].Cells[e.ColumnIndex].Value.ToString() != e.Value.ToString())
                        {
                            e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - 1, e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);
                        }
                        if (e.RowIndex == this.dataGridView1.Rows.Count - 1)
                        {
                            e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left + 2, e.CellBounds.Bottom - 1, e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);
                            count = 0;
                        }
                        //画grid右边线
                        //e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - 1, e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);
                        e.Graphics.DrawLine(gridLinePen, e.CellBounds.Right - 1, e.CellBounds.Top, e.CellBounds.Right - 1, e.CellBounds.Bottom);
                        e.Handled = true;
                    }
                }
                #endregion


                //}
            }
        }

最近整理自己写过的代码，发现datagridview行合并代码，已忘记是摘抄的网上的资料还是自己写的了，故此处无法写明参考自何处，如有哪位网友发现来源，麻烦请告知。在下还是很支持正版的。（整理进自己的博客里，方便查看阅读。O(∩_∩)O~~）