合并单元格的测试

纵向合并效果如下:

 横向合并效果如下:

以下是设计思路:因为代码比较简单,所以这里不多加解释.只说下遗憾,运行以下的代码时,发现在整个DATAGRID的列完全能显示的时候,绘制背景色没有问题,但,当有一部分行或列被挡住时,使用滚动条来移动,却发现有些DATAGRIDCELL的背景色被绘制窜行了,或者丢失了.而你左右多移动几下滚动条绘制又没有问题了,估计这是因为DATAGRIDVIEW本身绘制的机制问题,刷新的比较慢.所以在这里也只是提到这种简单的实现方法,如果有些朋友需要更高级的控制或更高级的要求,我想简单地通过这种在DATAGRIDVIEW里写代码的方式是行不通了.建议使用第3方控件或者干脆自己来做一个GRID吧!(呵呵,当然,做一个GRID是一个不小的工程,不过总觉得一旦能用代码实现它将是一劳永逸的,有时间一定要尝试下!呵呵!)

以下是源代码:

#region"合并单元格的测试"
        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())
                {
                    e.CellStyle.BackColor = Color.LightBlue;
                    nextcol = e.ColumnIndex + 1;
                }
            }
        }
        //==========================
       
        //绘制单元格
        private void dataGridView1_CellPainting(object sender, System.Windows.Forms.DataGridViewCellPaintingEventArgs e)
        {

 

            //纵向合并
            if (this.dataGridView1.Columns["description"].Index == e.ColumnIndex && 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);
                        ////绘制线条,这些线条是单元格相互间隔的区分线条,
                        ////因为我们只对列name做处理,所以datagridview自己会处理左侧和上边缘的线条
                        if (e.RowIndex != this.dataGridView1.RowCount - 1)
                        {
                            if (e.Value.ToString() != this.dataGridView1.Rows[e.RowIndex + 1].Cells[e.ColumnIndex].Value.ToString())
                            {

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

                        e.Handled = true;
                    }
                }
            }

            //横向合并
            if (this.dataGridView1.Columns["name"].Index == e.ColumnIndex && 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);

                        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((String)e.Value, 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