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 > -1 && e.ColumnIndex > -1)            {                DrawCell(e);            }            else            {                //二维表头                if (e.RowIndex == -1)                {                    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 + 2,                        right = e.CellBounds.Right, bottom = e.CellBounds.Bottom;                         switch (SpanRows[e.ColumnIndex].Position)                        {                            case 1:                                left += 2;                                break;                            case 2:                                break;                            case 3:                                right -= 2;                                break;                        }                         //画上半部分底色                        g.FillRectangle(new SolidBrush(this._mergecolumnheaderbackcolor), left, top,                        right - left, (bottom - top) / 2);                         //画中线                        g.DrawLine(new Pen(this.GridColor), left, (top + bottom) / 2,                        right, (top + bottom) / 2);                         //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) / 2, right - left, (bottom - top) / 2), sf);                        left = this.GetColumnDisplayRectangle(SpanRows[e.ColumnIndex].Left, true).Left - 2;                         if (left < 0) left = this.GetCellDisplayRectangle(-1, -1, true).Width;                        right = this.GetColumnDisplayRectangle(SpanRows[e.ColumnIndex].Right, true).Right - 2;                        if (right < 0) right = this.Width;                         g.DrawString(SpanRows[e.ColumnIndex].Text, e.CellStyle.Font, Brushes.Black,                        new Rectangle(left, top, right - left, (bottom - top) / 2), 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 - 4, e.RowBounds.Height);             TextRenderer.DrawText(e.Graphics,                (e.RowIndex + 1).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 = 0;        //下面相同的行数        int DownRows = 0;        //总行数        int count = 0;        if (this.MergeColumnNames.Contains(this.Columns[e.ColumnIndex].Name) && e.RowIndex != -1)        {            int cellwidth = e.CellBounds.Width;            var gridLinePen = new Pen(gridBrush);            string curValue = http://www.mamicode.com/e.Value =http://www.mamicode.com/= null ? "" : e.Value.ToString().Trim();            string curSelected = this.CurrentRow.Cells[e.ColumnIndex].Value =http://www.mamicode.com/= 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 >= 0; 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 - 1;                if (count < 2)                {                    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 == 1)            {                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;        }    }    /// <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) / 2, 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) / 2, e.CellBounds.Y - cellheight * (UpRows - 1) + (cellheight * count - fontheight) / 2);        }        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 - 1) + (cellheight * count - fontheight) / 2);        }        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 - 1) + (cellheight * count - fontheight) / 2);        }        else if (e.CellStyle.Alignment == DataGridViewContentAlignment.TopCenter)        {            e.Graphics.DrawString((String)e.Value, 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((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X, e.CellBounds.Y - cellheight * (UpRows - 1));        }        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 - 1));        }        else        {            e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / 2, e.CellBounds.Y - cellheight * (UpRows - 1) + (cellheight * count - fontheight) / 2);        }    }    #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 < 2)        {            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 - 1; //同一大标题下的最后一列的索引        SpanRows[ColIndex] = new SpanInfo(Text, 1, ColIndex, Right); //添加标题下的最左列        SpanRows[Right] = new SpanInfo(Text, 3, ColIndex, Right); //添加该标题下的最右列        for (int i = ColIndex + 1; i < Right; i++) //中间的列        {            SpanRows[i] = new SpanInfo(Text, 2, 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 - 1, -1, 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}

DataTable dt = new DataTable();     dt.Columns.Add("1");     dt.Columns.Add("2");     dt.Columns.Add("3");     dt.Columns.Add("4");     dt.Rows.Add("中国", "上海", "5000", "7000");     dt.Rows.Add("中国", "北京", "3000", "5600");     dt.Rows.Add("美国", "纽约", "6000", "8600");     dt.Rows.Add("美国", "华劢顿", "8000", "9000");     dt.Rows.Add("英国", "伦敦", "7000", "8800");     this.rowMergeView1.DataSource = dt;     this.rowMergeView1.ColumnHeadersHeight = 40;     this.rowMergeView1.ColumnHeadersHeightSizeMode = DataGridViewColumnHeadersHeightSizeMode.DisableResizing;     this.rowMergeView1.MergeColumnNames.Add("Column1");     this.rowMergeView1.AddSpanHeader(2, 2, "XXXX");