Datagridview 实现二维表头和行合并【转载】

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Design;
using System.Windows.Forms;

/// <summary>
/// DataGridView行合并.请对属性MergeColumnNames 赋值既可
/// </summary>
public partial class RowMergeView : DataGridView
{
    #region 构造函数
    public RowMergeView()
    {
        SetStyle(ControlStyles.DoubleBuffer | ControlStyles.OptimizedDoubleBuffer | ControlStyles.AllPaintingInWmPaint, true);
        UpdateStyles();
        InitializeComponent();
    }
    #endregion
    #region 重写的事件
    protected override void OnPaint(PaintEventArgs pe)
    {
        // TODO: 在此处添加自定义绘制代码

        // 调用基类 OnPaint
        base.OnPaint(pe);
    }
    protected override void OnCellPainting(DataGridViewCellPaintingEventArgs e)
    {
        try
        {
            if (e.RowIndex > - && e.ColumnIndex > -)
            {
                DrawCell(e);
            }
            else
            {
                //二维表头
                if (e.RowIndex == -)
                {
                    if (SpanRows.ContainsKey(e.ColumnIndex)) //被合并的列
                    {
                        //画边框
                        Graphics g = e.Graphics;
                        e.Paint(e.CellBounds, DataGridViewPaintParts.Background | DataGridViewPaintParts.Border);

                        int left = e.CellBounds.Left, top = e.CellBounds.Top + ,
                        right = e.CellBounds.Right, bottom = e.CellBounds.Bottom;

                        switch (SpanRows[e.ColumnIndex].Position)
                        {
                            case :
                                left += ;
                                break;
                            case :
                                break;
                            case :
                                right -= ;
                                break;
                        }

                        //画上半部分底色
                        g.FillRectangle(new SolidBrush(this._mergecolumnheaderbackcolor), left, top,
                        right - left, (bottom - top) / );

                        //画中线
                        g.DrawLine(new Pen(this.GridColor), left, (top + bottom) / ,
                        right, (top + bottom) / );

                        //写小标题
                        var sf = new StringFormat { Alignment = StringAlignment.Center, LineAlignment = StringAlignment.Center };

                        g.DrawString(e.Value + "", e.CellStyle.Font, Brushes.Black,
                        new Rectangle(left, (top + bottom) / , right - left, (bottom - top) / ), sf);
                        left = this.GetColumnDisplayRectangle(SpanRows[e.ColumnIndex].Left, true).Left - ;

                        if (left < ) left = this.GetCellDisplayRectangle(-, -, true).Width;
                        right = this.GetColumnDisplayRectangle(SpanRows[e.ColumnIndex].Right, true).Right - ;
                        if (right < ) right = this.Width;

                        g.DrawString(SpanRows[e.ColumnIndex].Text, e.CellStyle.Font, Brushes.Black,
                        new Rectangle(left, top, right - left, (bottom - top) / ), sf);
                        e.Handled = true;
                    }
                }
            }
            base.OnCellPainting(e);
        }
        catch
        { }
    }

    protected override void OnRowPostPaint(DataGridViewRowPostPaintEventArgs e)
    {
        if (this.RowHeadersVisible)
        {
            var rectangle = new Rectangle(e.RowBounds.Location.X, e.RowBounds.Location.Y, this.RowHeadersWidth - , e.RowBounds.Height);

            TextRenderer.DrawText(e.Graphics,
                (e.RowIndex + ).ToString(),
                this.RowHeadersDefaultCellStyle.Font,
                rectangle,
                this.RowHeadersDefaultCellStyle.ForeColor, TextFormatFlags.VerticalCenter | TextFormatFlags.Right);
        }

        base.OnRowPostPaint(e);
    }

    protected override void OnScroll(ScrollEventArgs e)
    {
        if (e.ScrollOrientation == ScrollOrientation.HorizontalScroll)// && e.Type == ScrollEventType.EndScroll)
        {
            timer1.Enabled = false;
            timer1.Enabled = true;
        }
    }

    #endregion
    #region 自定义方法
    /// <summary>
    /// 画单元格
    /// </summary>
    /// <param name="e"></param>
    private void DrawCell(DataGridViewCellPaintingEventArgs e)
    {
        if (e.CellStyle.Alignment == DataGridViewContentAlignment.NotSet)
        {
            e.CellStyle.Alignment = DataGridViewContentAlignment.MiddleCenter;
        }
        Brush gridBrush = new SolidBrush(this.GridColor);
        var backBrush = new SolidBrush(e.CellStyle.BackColor);
        var fontBrush = new SolidBrush(e.CellStyle.ForeColor);
        //上面相同的行数
        int UpRows = ;
        //下面相同的行数
        int DownRows = ;
        //总行数
        int count = ;
        if (this.MergeColumnNames.Contains(this.Columns[e.ColumnIndex].Name) && e.RowIndex != -)
        {
            int cellwidth = e.CellBounds.Width;
            var gridLinePen = new Pen(gridBrush);
            string curValue = e.Value == null ? "" : e.Value.ToString().Trim();
            string curSelected = this.CurrentRow.Cells[e.ColumnIndex].Value == null ? "" : this.CurrentRow.Cells[e.ColumnIndex].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))
                    {
                        //this.Rows[i].Cells[e.ColumnIndex].Selected = this.Rows[e.RowIndex].Cells[e.ColumnIndex].Selected;

                        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 >= ; i--)
                {
                    if (this.Rows[i].Cells[e.ColumnIndex].Value.ToString().Equals(curValue))
                    {
                        //this.Rows[i].Cells[e.ColumnIndex].Selected = this.Rows[e.RowIndex].Cells[e.ColumnIndex].Selected;
                        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 - ;
                if (count < )
                {
                    return;
                }
            }
            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 == )
            {
                e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - , e.CellBounds.Right - , e.CellBounds.Bottom - );
                count = ;
            }
            // 画右边线
            e.Graphics.DrawLine(gridLinePen, e.CellBounds.Right - , e.CellBounds.Top, e.CellBounds.Right - , e.CellBounds.Bottom);

            e.Handled = true;
        }
    }
    /// <summary>
    /// 画字符串
    /// </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)
    {
        var fontBrush = new SolidBrush(e.CellStyle.ForeColor);
        var fontheight = (int)e.Graphics.MeasureString(e.Value.ToString(), e.CellStyle.Font).Height;
        var 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((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / , e.CellBounds.Y + cellheight * DownRows - fontheight);
        }
        else if (e.CellStyle.Alignment == DataGridViewContentAlignment.BottomLeft)
        {
            e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X, e.CellBounds.Y + cellheight * DownRows - fontheight);
        }
        else if (e.CellStyle.Alignment == DataGridViewContentAlignment.BottomRight)
        {
            e.Graphics.DrawString((String)e.Value, 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((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / , e.CellBounds.Y - cellheight * (UpRows - ) + (cellheight * count - fontheight) / );
        }
        else if (e.CellStyle.Alignment == DataGridViewContentAlignment.MiddleLeft)
        {
            e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X, e.CellBounds.Y - cellheight * (UpRows - ) + (cellheight * count - fontheight) / );
        }
        else if (e.CellStyle.Alignment == DataGridViewContentAlignment.MiddleRight)
        {
            e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + cellwidth - fontwidth, e.CellBounds.Y - cellheight * (UpRows - ) + (cellheight * count - fontheight) / );
        }
        else if (e.CellStyle.Alignment == DataGridViewContentAlignment.TopCenter)
        {
            e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / , e.CellBounds.Y - cellheight * (UpRows - ));
        }
        else if (e.CellStyle.Alignment == DataGridViewContentAlignment.TopLeft)
        {
            e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X, e.CellBounds.Y - cellheight * (UpRows - ));
        }
        else if (e.CellStyle.Alignment == DataGridViewContentAlignment.TopRight)
        {
            e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + cellwidth - fontwidth, e.CellBounds.Y - cellheight * (UpRows - ));
        }
        else
        {
            e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / , e.CellBounds.Y - cellheight * (UpRows - ) + (cellheight * count - fontheight) / );
        }
    }
    #endregion
    #region 属性
    /// <summary>
    /// 设置或获取合并列的集合
    /// </summary>
    [MergableProperty(false)]
    [Editor("System.Windows.Forms.Design.ListControlStringCollectionEditor, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", typeof(UITypeEditor))]
    [DesignerSerializationVisibility(System.ComponentModel.DesignerSerializationVisibility.Visible)]
    [Localizable(true)]
    [Description("设置或获取合并列的集合"), Browsable(true), Category("单元格合并")]
    public List<string> MergeColumnNames
    {
        get
        {
            return _mergecolumnname;
        }
        set
        {
            _mergecolumnname = value;
        }
    }
    private List<string> _mergecolumnname = new List<string>();
    #endregion
    #region 二维表头
    private struct SpanInfo //表头信息
    {
        public SpanInfo(string Text, int Position, int Left, int Right)
        {
            this.Text = Text;
            this.Position = Position;
            this.Left = Left;
            this.Right = Right;
        }

        public readonly string Text; //列主标题
        public readonly int Position; //位置，1:左，2中，3右
        public readonly int Left; //对应左行
        public readonly int Right; //对应右行
    }
    private readonly Dictionary<int, SpanInfo> SpanRows = new Dictionary<int, SpanInfo>();//需要2维表头的列
    /// <summary>
    /// 合并列
    /// </summary>
    /// <param name="ColIndex">列的索引</param>
    /// <param name="ColCount">需要合并的列数</param>
    /// <param name="Text">合并列后的文本</param>
    public void AddSpanHeader(int ColIndex, int ColCount, string Text)
    {
        if (ColCount < )
        {
            throw new Exception("行宽应大于等于2，合并1列无意义。");
        }
        //将这些列加入列表
        int Right = ColIndex + ColCount - ; //同一大标题下的最后一列的索引
        SpanRows[ColIndex] = new SpanInfo(Text, , ColIndex, Right); //添加标题下的最左列
        SpanRows[Right] = new SpanInfo(Text, , ColIndex, Right); //添加该标题下的最右列
        for (int i = ColIndex + ; i < Right; i++) //中间的列
        {
            SpanRows[i] = new SpanInfo(Text, , ColIndex, Right);
        }
    }
    /// <summary>
    /// 清除合并的列
    /// </summary>
    public void ClearSpanInfo()
    {
        SpanRows.Clear();
        //ReDrawHead();
    }

    //刷新显示表头
    public void ReDrawHead()
    {
        foreach (int si in SpanRows.Keys)
        {
            this.Invalidate(this.GetCellDisplayRectangle(si - , -, true));
        }
    }
    private void timer1_Tick(object sender, EventArgs e)
    {
        timer1.Enabled = false;
        ReDrawHead();
    }
    /// <summary>
    /// 二维表头的背景颜色
    /// </summary>
    [Description("二维表头的背景颜色"), Browsable(true), Category("二维表头")]
    public Color MergeColumnHeaderBackColor
    {
        get { return this._mergecolumnheaderbackcolor; }
        set { this._mergecolumnheaderbackcolor = value; }
    }
    private Color _mergecolumnheaderbackcolor = System.Drawing.SystemColors.Control;
    #endregion
}

　需要新建一个组件类，拖放一个timer，你也可以不使用timer，直接把timer里面的方法放到调用的地方

使用：

DataTable dt = new DataTable();
     dt.Columns.Add("");
     dt.Columns.Add("");
     dt.Columns.Add("");
     dt.Columns.Add("");
     dt.Rows.Add("中国", "上海", "", "");
     dt.Rows.Add("中国", "北京", "", "");
     dt.Rows.Add("美国", "纽约", "", "");
     dt.Rows.Add("美国", "华劢顿", "", "");
     dt.Rows.Add("英国", "伦敦", "", "");
     this.rowMergeView1.DataSource = dt;
     this.rowMergeView1.ColumnHeadersHeight = ;
     this.rowMergeView1.ColumnHeadersHeightSizeMode = DataGridViewColumnHeadersHeightSizeMode.DisableResizing;
     this.rowMergeView1.MergeColumnNames.Add("Column1");
     this.rowMergeView1.AddSpanHeader(, , "XXXX");

　PS：http://www.cnblogs.com/greatverve/archive/2012/03/05/multi-datagridview.html

缺点：只能二维，不能多维