有个简易的方法：
2，添加CellPainting，代码如下：
private void DataGridViewEx_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
{
if (e.RowIndex == -)
{
// int w = dataGridView1.HorizontalScrollingOffset + dataGridView1.TopLeftHeaderCell.Size.Width + dataGridView1.Columns[0].Width + 10; Rectangle newRect = new Rectangle(e.CellBounds.X + ,
e.CellBounds.Y + , e.CellBounds.Width - ,
e.CellBounds.Height - ); using (
Brush gridBrush = new SolidBrush(this.GridColor),
backColorBrush = new SolidBrush(e.CellStyle.BackColor))
{
using (Pen gridLinePen = new Pen(gridBrush))
{
// Erase the cell.
e.Graphics.FillRectangle(backColorBrush, e.CellBounds); // Draw the grid lines (only the right and bottom lines;
// DataGridView takes care of the others).
e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left,
e.CellBounds.Bottom - , e.CellBounds.Right - ,
e.CellBounds.Bottom - );
if (e.ColumnIndex > - && topRow != null && topRow.Cells[e.ColumnIndex].ColSpan > )
{
e.Graphics.DrawLine(gridLinePen, e.CellBounds.Right - ,
e.CellBounds.Top + e.ClipBounds.Height / , e.CellBounds.Right - ,
e.CellBounds.Bottom);
}
else
{
e.Graphics.DrawLine(gridLinePen, e.CellBounds.Right - ,
e.CellBounds.Top, e.CellBounds.Right - ,
e.CellBounds.Bottom);
} // Draw the inset highlight box.
// e.Graphics.DrawRectangle(Pens.Blue, newRect); int scale = e.CellBounds.Height / ;
if (e.ColumnIndex > - && topRow.Cells[e.ColumnIndex].Text != null)
{
scale = e.CellBounds.Height / ;
e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - e.CellBounds.Height / , e.CellBounds.Right, e.CellBounds.Bottom - e.CellBounds.Height / );
}
// Draw the text content of the cell, ignoring alignment. if (e.Value != null)
{
e.Graphics.DrawString(e.Value.ToString(), e.CellStyle.Font,
Brushes.Crimson, e.CellBounds.X + ,
e.CellBounds.Y + scale + , StringFormat.GenericDefault); } if (e.ColumnIndex > - && topRow.Cells[e.ColumnIndex].RelateIndex > - && topRow.Cells[e.ColumnIndex].Text != null)
{
Rectangle recCell = new Rectangle(e.CellBounds.X - - topRow.Cells[e.ColumnIndex].SpanRowWith,
e.CellBounds.Y + , topRow.Cells[e.ColumnIndex].SpanRowWith,
e.CellBounds.Height / ); StringFormat sf = new StringFormat(); sf.Alignment = StringAlignment.Center; e.Graphics.DrawString(topRow.Cells[e.ColumnIndex].Text, e.CellStyle.Font, Brushes.Crimson, recCell, sf); } e.Handled = true;
}
}
} }
dataGridViewEx1.TopRow.Cells[2].Text = "入库"; dataGridViewEx1.TopRow.Cells[2].ColSpan = 2; dataGridViewEx1.TopRow.Cells[4].Text = "出库"; dataGridViewEx1.TopRow.Cells[4].ColSpan = 2;4，效果图
至于表尾合计，也做出了原型。二维表头+表尾合计，基本上满足需求了。
url:http://greatverve.cnblogs.com/archive/2012/03/05/Multi-DataGridView.html
1.DataGridView实现课程表 testcontrol.rar
2.DataGridView二维表头及单元格合并 DataGridView单元格合并和二维表头.rar myMultiColHeaderDgv.rar
3.DataGridView单元格显示GIF图片 gifanimationindatagrid.rar
4.自定义显示DataGridView列(行头显示行号与图标,同一单元格显示图片也显示文字)TestDataGridViewRowStyle2.rar
5.扩展DataGridView功能
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相关一些资料下载(收集自网络)
微软提供的例子 datagridviewsamples.rar
DataGridView使用文档 DataGridView_Doc.rar
Excel与DataGridView互导数据 Excl导入datagridview.rar
DataGridView扩展功能代码
--------------------------------------------------------------------------
还有用第三方控件的：
在做信息管理系统时，很多中式报表都是多维的，要实现报表数据显示，通常要用到多维表头。然而，非常遗憾的是，Winform中DataGrid、DataGridView本身不提供多维表头设计，要实现多维报表只好利用第三方的控件。通过对DataGridView的扩展，利用标题行进行重绘，可实现多维表头的友好界面。下面是对多维表头的探讨和实现。
1、常用多表头制作方法
a.第三方控件实现多维表头:FlexGrid--展示效果很好，就是数据量大加载时显示速度较慢。
b.报表方式实现多维表头：CrystalReport、Grid++Report--通过预览方式实现数据显示
c、DataGridView实现多维表头
2、DataGridView多维表头实现原理
通过重绘标题栏进行多栏实现,通过RowSpan和ColSpan来进行合并，类似Html的Table实现方式。
3、调用方法
private void Form1_Load(object sender, EventArgs e)
{
InitDataTable();
InitDataGridView();
}
DataTable table = new DataTable();
private void InitDataTable()
{
DataColumn col;
col = new DataColumn();
col.ColumnName = "客户名称";
table.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "产品名称";
table.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "规格";
table.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "单位";
table.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "期初存货数量";
col.DataType = System.Type.GetType("System.Decimal");
table.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "期初货款";
col.DataType = System.Type.GetType("System.Decimal");
table.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "期初帐款";
col.DataType = System.Type.GetType("System.Decimal");
table.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "发货数量";
col.DataType = System.Type.GetType("System.Decimal");
table.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "发货金额";
col.DataType = System.Type.GetType("System.Decimal");
table.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "开票数量";
col.DataType = System.Type.GetType("System.Decimal");
table.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "开票金额";
col.DataType = System.Type.GetType("System.Decimal");
table.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "回款数量";
col.DataType = System.Type.GetType("System.Decimal");
table.Columns.Add(col);
col = new DataColumn();
col.DataType = System.Type.GetType("System.Decimal");
col.ColumnName = "回款金额";
table.Columns.Add(col);
col = new DataColumn();
col.DataType = System.Type.GetType("System.Decimal");
col.ColumnName = "未开票回款数量";
table.Columns.Add(col);
col = new DataColumn();
col.DataType = System.Type.GetType("System.Decimal");
col.ColumnName = "未开票回款金额";
table.Columns.Add(col);
col = new DataColumn();
col.DataType = System.Type.GetType("System.Decimal");
col.ColumnName = "期末存货数量";
table.Columns.Add(col);
col = new DataColumn();
col.DataType = System.Type.GetType("System.Decimal");
col.ColumnName = "期末应收货款";
table.Columns.Add(col);
col = new DataColumn();
col.DataType = System.Type.GetType("System.Decimal");
col.ColumnName = "期末应收帐款";
table.Columns.Add(col);
}
private void InitDataGridView()
{
MutilGridHeader topRow = new MutilGridHeader();
topRow.SetRowCol(3, 18);
//第一行
topRow.Cells[0][0].Value = "客户";
topRow.Cells[0][0].RowSpan = 3;
topRow.Cells[0][1].Value = "产品名称";
topRow.Cells[0][1].RowSpan = 3;
topRow.Cells[0][2].Value = "规格";
topRow.Cells[0][2].RowSpan = 3;
topRow.Cells[0][3].Value = "单位";
topRow.Cells[0][3].RowSpan = 3;
topRow.Cells[0][4].Value = "期初";
topRow.Cells[0][4].ColSpan = 3;
topRow.Cells[0][7].Value = "本期";
topRow.Cells[0][7].ColSpan = 8;
topRow.Cells[0][15].Value = "期末";
topRow.Cells[0][15].ColSpan = 3;
//第二行
topRow.Cells[1][4].Value = "存货数量";
topRow.Cells[1][4].RowSpan = 2;
topRow.Cells[1][5].Value = "应收货款";
topRow.Cells[1][5].RowSpan = 2;
topRow.Cells[1][6].Value = "应收帐款";
topRow.Cells[1][6].RowSpan = 2;
topRow.Cells[1][7].Value = "发货";
topRow.Cells[1][7].ColSpan = 2;
topRow.Cells[1][9].Value = "开票";
topRow.Cells[1][9].ColSpan = 2;
topRow.Cells[1][11].Value = "回款";
topRow.Cells[1][11].ColSpan = 2;
topRow.Cells[1][13].Value = "未开票回款";
topRow.Cells[1][13].ColSpan = 2;
topRow.Cells[1][15].Value = "存货数量";
topRow.Cells[1][15].RowSpan = 2;
topRow.Cells[1][16].Value = "应收货款";
topRow.Cells[1][16].RowSpan = 2;
topRow.Cells[1][17].Value = "应收票款";
topRow.Cells[1][17].RowSpan = 2;
//第三行
topRow.Cells[2][7].Value = "数量";
topRow.Cells[2][8].Value = "金额";
topRow.Cells[2][9].Value = "数量";
topRow.Cells[2][10].Value = "金额";
topRow.Cells[2][11].Value = "数量";
topRow.Cells[2][12].Value = "金额";
topRow.Cells[2][13].Value = "数量";
topRow.Cells[2][14].Value = "金额";
dataGridViewEx1.Header = topRow;
dataGridViewEx1.DataSource = table;
table.DefaultView.AllowNew = false;
dataGridViewEx1.Columns[0].Width = 120;
dataGridViewEx1.Columns[1].Width = 100;
dataGridViewEx1.Columns[2].Width = 80;
for(int i = 2;i<18;i++)
dataGridViewEx1.Columns[i].Width = 60;
}
4、界面显示
这段代码是两年前写的，由于当时时间和编程水平有限，很多代码段没有加注释，代码的可读性极差,只是为了达到效果，具体合并的实现方法自己也已模糊。