最近经常看到关于DataGridView的Cell背景色、合并的提问，发个源代码

源代码也在blog上发布，有什么问题可以留言
http://blog.csdn.net/Samen168/archive/2007/01/23/1491310.aspx        private void Form1_Load(object sender, EventArgs e)
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("A");
            dt.Columns.Add("B");
            dt.Columns.Add("C");
            dt.Columns.Add("D");
            dt.Rows.Add(new object[] { "A1", "B1", "C1", "D1" });
            dt.Rows.Add(new object[] { "A2", "B2", "C2", "D2" });
            dt.Rows.Add(new object[] { "A3", "B3", "C3", "D3" });
            this.dataGridView1.DataSource = dt;        }        private void dataGridView1_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
        {            if (e.RowIndex < 0 || e.RowIndex >= this.dataGridView1.Rows.Count - 1 || e.ColumnIndex == -1)
            {
                return;
            }            // 假定需要将C列值为C3的单元格与前一单元格合并
            if (e.ColumnIndex == 1 && this.dataGridView1[e.RowIndex, e.ColumnIndex + 1].Value.ToString() == "C3")
            {
                e.Handled = true;
            }
            if (e.ColumnIndex == 2 &&  e.Value.ToString() == "C3")
            {
                DataGridViewCell preCell = this.dataGridView1[e.ColumnIndex -1, e.RowIndex];
                Rectangle re = new Rectangle(e.CellBounds.Left - this.dataGridView1.Columns[e.ColumnIndex - 1].Width
                    , e.CellBounds.Top, e.CellBounds.Width + this.dataGridView1.Columns[e.ColumnIndex - 1].Width, e.CellBounds.Height);
                e.Graphics.FillRectangle(Brushes.White,  re);                Pen pen = new Pen(this.dataGridView1.BackgroundColor,1);
                pen.DashStyle = System.Drawing.Drawing2D.DashStyle.Solid;
                e.Graphics.DrawLine(pen, re.X, re.Y + re.Height-1, re.X + re.Width, re.Y + re.Height-1);
                e.Graphics.DrawLine(pen, re.X + re.Width -1, re.Y , re.X + re.Width -1, re.Y + re.Height);                SizeF strSize = e.Graphics.MeasureString(e.Value.ToString(), this.dataGridView1.Font);
                e.Graphics.DrawString(e.Value.ToString(), this.dataGridView1.Font
                    , Brushes.Black, re.X, re.Y + (re.Height - strSize.Height) / 2);                e.Handled = true;
            }
        }        private void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
        {
            if(e.RowIndex != -1 && e.ColumnIndex == 1 && e.Value != null && e.Value.ToString() == "B1")
            {
                e.CellStyle.BackColor = Color.Red;
                e.CellStyle.ForeColor = Color.Blue;
                e.CellStyle.SelectionBackColor = Color.BlueViolet;
            }
        }    }