DataGridView合并单元格（多行多列合并）

一、点击在拖入的显示控件（TreeList）右上方的箭头，在Treelist任务中选择数据源，添加项目数据源，依次选择数据库、数据集，新建连接，浏览选择数据库（*.mdb），依次点击 下一步，选择“表”，完成。

二、具体代码如下：

        #region"合并单元格(多行多列)"

        //需要(行、列)合并的所有列标题名
        List<String> colsHeaderText_V = new List<String>();
        List<String> colsHeaderText_H = new List<String>();

        private void InitFormatColumns()
        {
            colsHeaderText_V.Add("PHONE1");
            colsHeaderText_V.Add("PHONE2");

            colsHeaderText_H.Add("IMAGEINDEX");
            colsHeaderText_H.Add("PARENTID");
            colsHeaderText_H.Add("DEPARTMENT");
            colsHeaderText_H.Add("LOCATION");
        }


        //绘制单元格
        private void dataGridView1_CellPainting(object sender, System.Windows.Forms.DataGridViewCellPaintingEventArgs e)
        {
            foreach (string fieldHeaderText in colsHeaderText_H)
            {
                //纵向合并
                if (e.ColumnIndex >= 0 && this.dataGridView1.Columns[e.ColumnIndex].HeaderText == fieldHeaderText && e.RowIndex >= 0)
                {
                    using (
                        Brush gridBrush = new SolidBrush(this.dataGridView1.GridColor),
                        backColorBrush = new SolidBrush(e.CellStyle.BackColor))
                    {
                        using (Pen gridLinePen = new Pen(gridBrush))
                        {
                            // 擦除原单元格背景
                            e.Graphics.FillRectangle(backColorBrush, e.CellBounds);

                            /****** 绘制单元格相互间隔的区分线条，datagridview自己会处理左侧和上边缘的线条，因此只需绘制下边框和和右边框
                             DataGridView控件绘制单元格时，不绘制左边框和上边框，共用左单元格的右边框，上一单元格的下边框*****/

                            //不是最后一行且单元格的值不为null
                            if (e.RowIndex < this.dataGridView1.RowCount - 1 && this.dataGridView1.Rows[e.RowIndex + 1].Cells[e.ColumnIndex].Value != null)
                            {
                                //若与下一单元格值不同
                                if (e.Value.ToString() != this.dataGridView1.Rows[e.RowIndex + 1].Cells[e.ColumnIndex].Value.ToString())
                                {
                                    //下边缘的线
                                    e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - 1,
                                    e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);
                                    //绘制值
                                    if (e.Value != null)
                                    {
                                        e.Graphics.DrawString(e.Value.ToString(), e.CellStyle.Font,
                                            Brushes.Crimson, e.CellBounds.X + 2,
                                            e.CellBounds.Y + 2, StringFormat.GenericDefault);
                                    }
                                }
                                //若与下一单元格值相同  
                                else
                                {
                                    //背景颜色
                                    //e.CellStyle.BackColor = Color.LightPink;   //仅在CellFormatting方法中可用
                                    this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Style.BackColor = Color.LightBlue;
                                    this.dataGridView1.Rows[e.RowIndex + 1].Cells[e.ColumnIndex].Style.BackColor = Color.LightBlue;
                                    //只读（以免双击单元格时显示值）
                                    this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].ReadOnly = true;
                                    this.dataGridView1.Rows[e.RowIndex + 1].Cells[e.ColumnIndex].ReadOnly = true;
                                }
                            }
                            //最后一行或单元格的值为null
                            else
                            {
                                //下边缘的线
                                e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - 1,
                                    e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);

                                //绘制值
                                if (e.Value != null)
                                {
                                    e.Graphics.DrawString(e.Value.ToString(), e.CellStyle.Font,
                                        Brushes.Crimson, e.CellBounds.X + 2,
                                        e.CellBounds.Y + 2, StringFormat.GenericDefault);
                                }
                            }

                            ////左侧的线（）
                            //e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left,
                            //    e.CellBounds.Top, e.CellBounds.Left,
                            //    e.CellBounds.Bottom - 1);

                            //右侧的线
                            e.Graphics.DrawLine(gridLinePen, e.CellBounds.Right - 1,
                                e.CellBounds.Top, e.CellBounds.Right - 1,
                                e.CellBounds.Bottom - 1);

                            //设置处理事件完成（关键点），只有设置为ture,才能显示出想要的结果。
                            e.Handled = true;
                        }
                    }
                }
            }

            foreach (string fieldHeaderText in colsHeaderText_V)
            {
                //横向合并
                if (e.ColumnIndex >= 0 && this.dataGridView1.Columns[e.ColumnIndex].HeaderText == fieldHeaderText && e.RowIndex >= 0)
                {
                    using (
                        Brush gridBrush = new SolidBrush(this.dataGridView1.GridColor),
                        backColorBrush = new SolidBrush(e.CellStyle.BackColor))
                    {
                        using (Pen gridLinePen = new Pen(gridBrush))
                        {
                            // 擦除原单元格背景
                            e.Graphics.FillRectangle(backColorBrush, e.CellBounds);

                            /****** 绘制单元格相互间隔的区分线条，datagridview自己会处理左侧和上边缘的线条，因此只需绘制下边框和和右边框
                             DataGridView控件绘制单元格时，不绘制左边框和上边框，共用左单元格的右边框，上一单元格的下边框*****/

                            //不是最后一列且单元格的值不为null
                            if (e.ColumnIndex < this.dataGridView1.ColumnCount - 1 && this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex + 1].Value != null)
                            {
                                if (e.Value.ToString() != this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex + 1].Value.ToString())
                                {
                                    //右侧的线
                                    e.Graphics.DrawLine(gridLinePen, e.CellBounds.Right - 1, e.CellBounds.Top,
                                        e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);
                                    //绘制值
                                    if (e.Value != null)
                                    {
                                        e.Graphics.DrawString(e.Value.ToString(), e.CellStyle.Font,
                                            Brushes.Crimson, e.CellBounds.X + 2,
                                            e.CellBounds.Y + 2, StringFormat.GenericDefault);
                                    }
                                }
                                //若与下一单元格值相同  
                                else
                                {
                                    //背景颜色
                                    //e.CellStyle.BackColor = Color.LightPink;   //仅在CellFormatting方法中可用
                                    this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Style.BackColor = Color.LightPink;
                                    this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex + 1].Style.BackColor = Color.LightPink;
                                    //只读（以免双击单元格时显示值）
                                    this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].ReadOnly = true;
                                    this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex + 1].ReadOnly = true;
                                }
                            }
                            else
                            {
                                //右侧的线
                                e.Graphics.DrawLine(gridLinePen, e.CellBounds.Right - 1, e.CellBounds.Top,
                                    e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);

                                //绘制值
                                if (e.Value != null)
                                {
                                    e.Graphics.DrawString(e.Value.ToString(), e.CellStyle.Font,
                                        Brushes.Crimson, e.CellBounds.X + 2,
                                        e.CellBounds.Y + 2, StringFormat.GenericDefault);
                                }
                            }
                            //下边缘的线
                            e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - 1,
                                                        e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);
                            e.Handled = true;
                        }
                    }

                }
            }

        }
        #endregion

额外：

//添加序列号
private void dataGridView1_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs e)
        {
             SolidBrush b = new SolidBrush(this.dataGridView1.RowHeadersDefaultCellStyle.ForeColor);
             e.Graphics.DrawString((e.RowIndex + 1).ToString(System.Globalization.CultureInfo.CurrentUICulture), this.dataGridView1.DefaultCellStyle.Font,b,e.RowBounds.Location.X + 20,e.RowBounds.Location.Y + 4);
         }