datagridview 纵向 横向 合并单元格

datagridview 单元格合并：纵向以及横向合并参考了csdn上不知哪位的代码，具体哪位找不到连接了。

纵向合并：

        /// <summary>
        /// 纵向合并,即合并数据项的值
        /// </summary>
        /// <param name="e"></param>
        private void DrawCellVer(DataGridViewCellPaintingEventArgs e)
        {
            if (e.CellStyle.Alignment != DataGridViewContentAlignment.MiddleCenter)
            {
                e.CellStyle.Alignment = DataGridViewContentAlignment.MiddleCenter;
            }
            Brush gridBrush = new SolidBrush(this.GridColor);
            SolidBrush backBrush = new SolidBrush(e.CellStyle.BackColor);
            int cellwidth;
            //上面相同的行数
            int UpRows = 0;
            //下面相同的行数
            int DownRows = 0;
            //总行数
            int count = 0;
            if (true)
            {
                cellwidth = e.CellBounds.Width;
                Pen gridLinePen = new Pen(gridBrush);
                //获取当前单元格的值，如果为null,就赋值为＂＂
                string curValue = e.Value == null ? "" : e.Value.ToString().Trim();
                if (!string.IsNullOrEmpty(curValue))
                {
                    #region 获取下面的行数
                    for (int i = e.RowIndex; i < this.Rows.Count; i++)
                    {
                        if (this.Rows[i].Cells[e.ColumnIndex].Value.ToString().Equals(curValue))
                        {
                            DownRows++;
                            if (e.RowIndex != i)
                            {
                                cellwidth = cellwidth < this.Rows[i].Cells[e.ColumnIndex].Size.Width ? cellwidth : this.Rows[i].Cells[e.ColumnIndex].Size.Width;
                            }
                        }
                        else
                            break;
                    }
                    #endregion

                    #region 获取上面的行数
                    for (int i = e.RowIndex; i >= 0; i--)
                    {
                        if (this.Rows[i].Cells[e.ColumnIndex].Value.ToString().Equals(curValue))
                        {
                            UpRows++;
                            if (e.RowIndex != i)
                            {
                                cellwidth = cellwidth < this.Rows[i].Cells[e.ColumnIndex].Size.Width ? cellwidth : this.Rows[i].Cells[e.ColumnIndex].Size.Width;
                            }
                        }
                        else
                            break;
                    }
                    #endregion
                    count = DownRows + UpRows - 1;

                    if (count < 2)
                    {
                        return;
                    }
                }
                else
                {
                    //取下面看是否有为空的单元格,如果为最后一个为空的单元格，则画下边线
                    if (e.RowIndex < this.Rows.Count - 1)
                    {
                        if (this.Rows[e.RowIndex + 1].Cells[e.ColumnIndex].Value != DBNull.Value)
                        {
                            if (!string.IsNullOrEmpty(this.Rows[e.RowIndex + 1].Cells[e.ColumnIndex].Value.ToString()))
                            {
                                DownRows = 1;
                            }

                        }
                    }
                }
                if (this.Rows[e.RowIndex].Selected)
                {
                    backBrush.Color = e.CellStyle.SelectionBackColor;
                    //fontBrush.Color = e.CellStyle.SelectionForeColor;
                }
                //以背景色填充
                e.Graphics.FillRectangle(backBrush, e.CellBounds);
                //画字符串
                PaintingFont(e, cellwidth, UpRows, DownRows, count);
                if (DownRows == 1)
                {
                    //画下面的线
                    e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - 1, e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);
                    count = 0;
                }
                // 画右边线
                e.Graphics.DrawLine(gridLinePen, e.CellBounds.Right - 1, e.CellBounds.Top, e.CellBounds.Right - 1, e.CellBounds.Bottom);

                e.Handled = true;
            }
        }

　　横向合并：

        /// <summary>
        /// 水平合并单元格，即数据头的合并
        /// </summary>
        /// <param name="e"></param>
        private void DrawCellHor(DataGridViewCellPaintingEventArgs e)
        {
            if (e.CellStyle.Alignment != DataGridViewContentAlignment.MiddleCenter)
            {
                e.CellStyle.Alignment = DataGridViewContentAlignment.MiddleCenter;
            }
            Brush gridBrush = new SolidBrush(this.GridColor);
            SolidBrush backBrush = new SolidBrush(e.CellStyle.BackColor);
            int cellwidth;
            //前面相同的行数
            int BefRows = 0;
            //后面相同的行数
            int BehRows = 0;
            //总列数
            int count = 0;
            if (true)
            {
                cellwidth = e.CellBounds.Width;
                Pen gridLinePen = new Pen(gridBrush);
                //获取当前单元格的值，如果为null,就赋值为＂＂
                string curValue = e.Value == null ? "" : e.Value.ToString().Trim();
                if (!string.IsNullOrEmpty(curValue))
                {
                    #region 获取后面的列数
                    for (int i = e.ColumnIndex; i < this.ColumnCount; i++)
                    {
                        if (this.Rows[e.RowIndex].Cells[i].Value.ToString().Equals(curValue))
                        {
                            BehRows++;
                            if (e.ColumnIndex != i)
                            {
                                cellwidth = cellwidth < this.Rows[e.RowIndex].Cells[i].Size.Width ? cellwidth : this.Rows[e.RowIndex].Cells[i].Size.Width;
                            }
                        }
                        else
                            break;
                    }
                    #endregion

                    #region 获取前面的列数
                    for (int i = e.ColumnIndex; i >= 0; i--)
                    {
                        if (this.Rows[e.RowIndex].Cells[i].Value.ToString().Equals(curValue))
                        {
                            BefRows++;
                            if (e.ColumnIndex != i)
                            {
                                cellwidth = cellwidth < this.Rows[e.RowIndex].Cells[i].Size.Width ? cellwidth : this.Rows[e.RowIndex].Cells[i].Size.Width;
                            }
                        }
                        else
                            break;
                    }
                    #endregion
                    count = BehRows + BefRows - 1;

                    if (count < 2)
                    {
                        return;
                    }
                }
                else
                {
                    //取右边看是否有为空的单元格,如果为最后一个为空的单元格，则画右侧线
                    if (e.ColumnIndex < this.ColumnCount - 1)
                    {
                        if (this.Rows[e.RowIndex].Cells[e.ColumnIndex+1].Value != DBNull.Value)
                        {
                            if (!string.IsNullOrEmpty(this.Rows[e.RowIndex].Cells[e.ColumnIndex+1].Value.ToString()))
                            {
                                BehRows = 1;
                            }

                        }
                    }
                }
                if (this.Rows[e.RowIndex].Selected)
                {
                    backBrush.Color = e.CellStyle.SelectionBackColor;
                    //fontBrush.Color = e.CellStyle.SelectionForeColor;
                }
                //以背景色填充
                e.Graphics.FillRectangle(backBrush, e.CellBounds);
                //画字符串
                HorPaintingFont(e, cellwidth, BefRows, BehRows, count);
                if (BehRows == 1)
                {
                    //画右边缘的线
                    e.Graphics.DrawLine(gridLinePen, e.CellBounds.Right - 1, e.CellBounds.Top, e.CellBounds.Right - 1, e.CellBounds.Bottom);
                    count = 0;
                }
                // 画下边缘的线
                e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - 1, e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);

                e.Handled = true;
            }
        }

　单元格写值纵向：

        /// <summary>
        /// 绘制合并以后的值(纵向)
        /// </summary>
        /// <param name="e"></param>
        /// <param name="cellwidth"></param>
        /// <param name="UpRows"></param>
        /// <param name="DownRows"></param>
        /// <param name="count"></param>
        private void PaintingFont(System.Windows.Forms.DataGridViewCellPaintingEventArgs e, int cellwidth, int UpRows, int DownRows, int count)
        {
            if (e.Value != DBNull.Value)
            {
                stValue = e.Value.ToString();
            }
            using (SolidBrush fontBrush = new SolidBrush(e.CellStyle.ForeColor))
            {
                fontheight = (int)e.Graphics.MeasureString(e.Value.ToString(), e.CellStyle.Font).Height;
                fontwidth = (int)e.Graphics.MeasureString(e.Value.ToString(), e.CellStyle.Font).Width;
                int cellheight = e.CellBounds.Height;

                if (e.CellStyle.Alignment == DataGridViewContentAlignment.BottomCenter)
                {
                    e.Graphics.DrawString(stValue, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / 2, e.CellBounds.Y + cellheight * DownRows - fontheight);
                }
                else if (e.CellStyle.Alignment == DataGridViewContentAlignment.BottomLeft)
                {
                    e.Graphics.DrawString(stValue, e.CellStyle.Font, fontBrush, e.CellBounds.X, e.CellBounds.Y + cellheight * DownRows - fontheight);
                }
                else if (e.CellStyle.Alignment == DataGridViewContentAlignment.BottomRight)
                {
                    e.Graphics.DrawString(stValue, e.CellStyle.Font, fontBrush, e.CellBounds.X + cellwidth - fontwidth, e.CellBounds.Y + cellheight * DownRows - fontheight);
                }
                else if (e.CellStyle.Alignment == DataGridViewContentAlignment.MiddleCenter)
                {

                    e.Graphics.DrawString(stValue, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / 2, e.CellBounds.Y - cellheight * (UpRows - 1) + (cellheight * count - fontheight) / 2);
                }
                else if (e.CellStyle.Alignment == DataGridViewContentAlignment.MiddleLeft)
                {
                    e.Graphics.DrawString(stValue, e.CellStyle.Font, fontBrush, e.CellBounds.X, e.CellBounds.Y - cellheight * (UpRows - 1) + (cellheight * count - fontheight) / 2);
                }
                else if (e.CellStyle.Alignment == DataGridViewContentAlignment.MiddleRight)
                {
                    e.Graphics.DrawString(stValue, e.CellStyle.Font, fontBrush, e.CellBounds.X + cellwidth - fontwidth, e.CellBounds.Y - cellheight * (UpRows - 1) + (cellheight * count - fontheight) / 2);
                }
                else if (e.CellStyle.Alignment == DataGridViewContentAlignment.TopCenter)
                {
                    e.Graphics.DrawString(stValue, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / 2, e.CellBounds.Y - cellheight * (UpRows - 1));
                }
                else if (e.CellStyle.Alignment == DataGridViewContentAlignment.TopLeft)
                {
                    e.Graphics.DrawString(stValue, e.CellStyle.Font, fontBrush, e.CellBounds.X, e.CellBounds.Y - cellheight * (UpRows - 1));
                }
                else if (e.CellStyle.Alignment == DataGridViewContentAlignment.TopRight)
                {
                    e.Graphics.DrawString(stValue, e.CellStyle.Font, fontBrush, e.CellBounds.X + cellwidth - fontwidth, e.CellBounds.Y - cellheight * (UpRows - 1));
                }
                else
                {
                    e.Graphics.DrawString(stValue, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / 2, e.CellBounds.Y - cellheight * (UpRows - 1) + (cellheight * count - fontheight) / 2);
                }
            }
        }

　　单元格写值横向：

        /// <summary>
        /// 水平方向写值
        /// </summary>
        /// <param name="e"></param>
        /// <param name="cellwidth"></param>
        /// <param name="UpRows"></param>
        /// <param name="DownRows"></param>
        /// <param name="count"></param>
        private void HorPaintingFont(System.Windows.Forms.DataGridViewCellPaintingEventArgs e, int cellwidth, int UpRows, int DownRows, int count)
        {
            using (SolidBrush fontBrush = new SolidBrush(e.CellStyle.ForeColor))
            {
                fontheight = (int)e.Graphics.MeasureString(e.Value.ToString(), e.CellStyle.Font).Height;
                fontwidth = (int)e.Graphics.MeasureString(e.Value.ToString(), e.CellStyle.Font).Width;
                int cellHeight = e.CellBounds.Height;

                if (e.Value != DBNull.Value)
                {
                    stValue = e.Value.ToString();
                }
                if (e.CellStyle.Alignment == DataGridViewContentAlignment.MiddleCenter)
                {
                    e.Graphics.DrawString(stValue, e.CellStyle.Font, fontBrush, e.CellBounds.X - cellwidth * (UpRows - 1) + (cellwidth * count - fontwidth) / 2, e.CellBounds.Y + (cellHeight - fontheight) / 2);
                }
            }
        }

　　在次备忘一下。