WinForm下DataGridView如何对Header进行Merge Cell

在网上找到这方面的源代码。

http://social.msdn.microsoft.com/Forums/windows/en-US/87004d70-482a-4b86-ba18-371670254b6a/how-to-merge-headers-in-a-datagridview

http://www.codeproject.com/Questions/152113/How-can-i-merge-DataGridView-Rows-Cells-with-Equal

http://forums.codeguru.com/showthread.php?415930-DataGridView-Merging-Cells

namespace Sample5

{

    public partial class DgvColumnHeaderMerge : Form

    {

        public DgvColumnHeaderMerge()

        {

            InitializeComponent();

        }

        private void DgvColumnHeaderMerge_Load(object sender, EventArgs e)

        {

            this.dataGridView1.Columns.Add("JanWin", "Win");

            this.dataGridView1.Columns.Add("JanLoss", "Loss");

            this.dataGridView1.Columns.Add("FebWin", "Win");

            this.dataGridView1.Columns.Add("FebLoss", "Loss");

            this.dataGridView1.Columns.Add("MarWin", "Win");

            this.dataGridView1.Columns.Add("MarLoss", "Loss");

            this.dataGridView1.Columns.Add("AprWin", "Win");

            this.dataGridView1.Columns.Add("AprLoss", "Loss");

            this.dataGridView1.Columns.Add("MayWin", "Win");

            this.dataGridView1.Columns.Add("MayLoss", "Loss");

            for (int j = 0; j < this.dataGridView1.ColumnCount; j++)

            {

                this.dataGridView1.Columns[j].Width = 45;

            }

            this.dataGridView1.ColumnHeadersHeightSizeMode = DataGridViewColumnHeadersHeightSizeMode.EnableResizing;

            this.dataGridView1.ColumnHeadersHeight = this.dataGridView1.ColumnHeadersHeight * 2;

            this.dataGridView1.ColumnHeadersDefaultCellStyle.Alignment = DataGridViewContentAlignment.BottomCenter;

            this.dataGridView1.CellPainting += new DataGridViewCellPaintingEventHandler(dataGridView1_CellPainting);

            this.dataGridView1.Paint += new PaintEventHandler(dataGridView1_Paint);

            this.dataGridView1.Scroll += new ScrollEventHandler(dataGridView1_Scroll);

            this.dataGridView1.ColumnWidthChanged += new DataGridViewColumnEventHandler(dataGridView1_ColumnWidthChanged);

        }

        void dataGridView1_ColumnWidthChanged(object sender, DataGridViewColumnEventArgs e)

        {

            Rectangle rtHeader = this.dataGridView1.DisplayRectangle;

            rtHeader.Height = this.dataGridView1.ColumnHeadersHeight / 2;

            this.dataGridView1.Invalidate(rtHeader);

        }

        void dataGridView1_Scroll(object sender, ScrollEventArgs e)

        {

            Rectangle rtHeader = this.dataGridView1.DisplayRectangle;

            rtHeader.Height = this.dataGridView1.ColumnHeadersHeight / 2;

            this.dataGridView1.Invalidate(rtHeader);

        }

        void dataGridView1_Paint(object sender, PaintEventArgs e)

        {

            string[] monthes = { "January", "February", "March","April" ,"May"};

            for (int j = 0; j < 10;)

            {

                Rectangle r1 = this.dataGridView1.GetCellDisplayRectangle(j, -1,true);

                int w2 = this.dataGridView1.GetCellDisplayRectangle(j + 1, -1, true).Width;

                r1.X += 1;

                r1.Y += 1;

                r1.Width = r1.Width + w2 - 2;

                r1.Height = r1.Height / 2 - 2;

                e.Graphics.FillRectangle(new SolidBrush(this.dataGridView1.ColumnHeadersDefaultCellStyle.BackColor), r1);

                StringFormat format = new StringFormat();

                format.Alignment = StringAlignment.Center;

                format.LineAlignment = StringAlignment.Center;

                e.Graphics.DrawString(monthes[j/2],

                    this.dataGridView1.ColumnHeadersDefaultCellStyle.Font,

                    new SolidBrush(this.dataGridView1.ColumnHeadersDefaultCellStyle.ForeColor),

                    r1,

                    format);

                j += 2;

            }

        }

        void dataGridView1_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)

        {

            if (e.RowIndex == -1 && e.ColumnIndex > -1)

            {

                Rectangle r2 = e.CellBounds;

                r2.Y += e.CellBounds.Height / 2;

                r2.Height = e.CellBounds.Height / 2;

                e.PaintBackground(r2, true);

               

                e.PaintContent(r2);

                e.Handled = true;

            }

        }

    }

}