DataGridView控件重绘

 public partial class WDataGridView : DataGridView
    {
        public WDataGridView()
        {
            InitializeComponent();

            SetStyle(ControlStyles.SupportsTransparentBackColor |
             ControlStyles.OptimizedDoubleBuffer |
             ControlStyles.ResizeRedraw |
             ControlStyles.UserPaint, true);
        }

        public WDataGridView(IContainer container)
        {
            container.Add(this);

            InitializeComponent();
        }


        private Color m_colorAlternatingRowsBack = Color.FromArgb(255, 255, 255);
        [Description("奇数行颜色")]
        public Color ColorAlternatingRowsBack
        {
            get { return m_colorAlternatingRowsBack; }
            set
            {
                m_colorAlternatingRowsBack = value;
                AlternatingRowsDefaultCellStyle.BackColor = value;
            }
        }

        private Color m_colorDefaultRowsBack = Color.FromArgb(235, 235, 235);
        [Description("默认行颜色")]
        public Color ColorDefaultRowsBack
        {
            get { return m_colorDefaultRowsBack; }
            set
            {
                m_colorDefaultRowsBack = value;
                RowsDefaultCellStyle.BackColor = value;
            }
        }

        private Color m_colorDefaultRowsFore = Color.FromArgb(0, 0, 0);
        [Description("默认行字体颜色")]
        public Color ColorDefaultRowsFore
        {
            get { return m_colorDefaultRowsFore; }
            set
            {
                m_colorDefaultRowsFore = value;
                RowsDefaultCellStyle.ForeColor = value;
            }
        }

        private Color m_colorDefaultRowsSelectBack = Color.FromArgb(100, 255, 255);
        [Description("选中行颜色")]
        public Color ColorDefaultRowsSelectBack
        {
            get { return m_colorDefaultRowsSelectBack; }
            set
            {
                m_colorDefaultRowsSelectBack = value;
                RowsDefaultCellStyle.SelectionBackColor = value;
            }
        }

        private Color m_colorDefaultRowsSelectFore = Color.FromArgb(0, 0, 0);
        [Description("选中行字体颜色")]
        public Color ColorDefaultRowsSelectFore
        {
            get { return m_colorDefaultRowsSelectFore; }
            set
            {
                m_colorDefaultRowsSelectFore = value;
                RowsDefaultCellStyle.SelectionForeColor = value;
            }
        }

        private void DgvStyle(DataGridView dgv)
        {
            dgv.RowHeadersVisible = false;
            //奇数行的背景色
            dgv.AlternatingRowsDefaultCellStyle.BackColor = System.Drawing.Color.FromArgb(255, 255, 255);
            //默认的行样式
            dgv.RowsDefaultCellStyle.BackColor = System.Drawing.Color.FromArgb(180, 180, 180);
            dgv.RowsDefaultCellStyle.SelectionBackColor = System.Drawing.Color.FromArgb(0, 255, 255);
            dgv.RowsDefaultCellStyle.SelectionForeColor = System.Drawing.Color.FromArgb(0, 0, 0);

            //数据网格颜色
            //dgv.GridColor = System.Drawing.Color.FromArgb(((int)(((byte)(0)))), ((int)(((byte)(0)))), ((int)(((byte)(192)))));
            dgv.GridColor = System.Drawing.Color.Gray;
            //列标题的宽度
            dgv.ColumnHeadersHeight = 30;
            // dgv.ReadOnly = true;
            //dgv.AllowUserToResizeColumns = false;
            //dgv.AllowUserToResizeRows = false;

            this.AllowDrop = true;
            //this.MultiSelect = false;
            this.SelectionMode = DataGridViewSelectionMode.FullRowSelect;//点击单元格选中整行
        }


        private bool m_bDrawBorder = true;
        [Description("是否绘制边框")]
        public bool bDrawBorder
        {
            get { return m_bDrawBorder; }
            set { m_bDrawBorder = value; Invalidate(); }
        }

        private Color m_clHeadStart = Color.FromArgb(242, 243, 245);
        [Description("标头背景渐变开始颜色")]
        public Color HeadStart
        {
            get { return m_clHeadStart; }
            set { m_clHeadStart = value; Invalidate(); }
        }

        private Color m_clHeadStop = Color.FromArgb(242, 243, 245);
        [Description("标头背景渐变结束颜色")]
        public Color HeadStop
        {
            get { return m_clHeadStop; }
            set { m_clHeadStop = value; Invalidate(); }
        }

        private Color m_clHeadText = Color.Black;
        [Description("标头字体颜色")]
        public Color ColorHeadText
        {
            get { return m_clHeadText; }
            set { m_clHeadText = value; Invalidate(); }
        }

        private DataGridViewContentAlignment m_CellTextAlign = DataGridViewContentAlignment.MiddleLeft;
        [Description("单元格文本对齐方式")]
        public DataGridViewContentAlignment CellTextAlign
        {
            get { return m_CellTextAlign;} 
            set { m_CellTextAlign = value; Invalidate();}
        }

        /// <summary>
        /// 绘制单元格事件
        /// </summary>
        /// <param name="e"></param>
        protected override void OnCellPainting(DataGridViewCellPaintingEventArgs e)
        {
            base.OnCellPainting(e);

            e.CellStyle.Alignment = m_CellTextAlign;//单元格内容集中

            bool bDrawBorder = true;

            if (e.ColumnIndex == -1 && e.RowIndex == -1)
            {
                using (LinearGradientBrush brush = new LinearGradientBrush(e.CellBounds, m_clHeadStart, m_clHeadStop, LinearGradientMode.ForwardDiagonal))              
                {
                    e.Graphics.FillRectangle(brush, e.CellBounds);
                    Rectangle border = e.CellBounds;
                    border.Offset(new Point(-1, -1));
                    if (m_bDrawBorder)
                        e.Graphics.DrawRectangle(Pens.Gray, border);//绘制边框
                    
                }
                //e.PaintContent(e.CellBounds);
                //绘制标头
                if (e.Value != null)
                {
                    StringFormat sf = new StringFormat();
                    sf.Alignment = StringAlignment.Center;
                    sf.LineAlignment = StringAlignment.Center;
                    
                    e.Graphics.DrawString(e.Value.ToString(), new Font("微软雅黑", 11), Brushes.Black, e.CellBounds, sf);
                }
                e.Handled = true;
            }
            else if (e.RowIndex == -1)
            {
                //标题行
                using (LinearGradientBrush brush = new LinearGradientBrush(e.CellBounds, m_clHeadStart, m_clHeadStop, LinearGradientMode.Vertical))
                {
                    e.Graphics.FillRectangle(brush, e.CellBounds);
                    Rectangle border = e.CellBounds;
                    border.Offset(new Point(-1, -1));
                    if (m_bDrawBorder)
                        e.Graphics.DrawRectangle(Pens.Gray, border);//绘制边框
                }
                //e.PaintContent(e.CellBounds);

                if (e.Value != null)
                {
                    StringFormat sf = new StringFormat();
                    sf.Alignment = StringAlignment.Center;
                    sf.LineAlignment = StringAlignment.Center;                  
                    e.Graphics.DrawString(e.Value.ToString(), new Font("微软雅黑", 11), new SolidBrush(m_clHeadText), e.CellBounds, sf);
                }

                e.Handled = true;
            }
            else if (e.ColumnIndex == -1)
            {
                //标题列
                using (LinearGradientBrush brush = new LinearGradientBrush(e.CellBounds, m_clHeadStart, m_clHeadStop, LinearGradientMode.Horizontal))
                {
                    e.Graphics.FillRectangle(brush, e.CellBounds);
                    Rectangle border = e.CellBounds;
                    border.Offset(new Point(-1, -1));
                    if (m_bDrawBorder)
                        e.Graphics.DrawRectangle(Pens.Gray, border);
                }
                //e.PaintContent(e.CellBounds);

                if (e.Value != null)
                {
                    StringFormat sf = new StringFormat();
                    sf.Alignment = StringAlignment.Center;
                    sf.LineAlignment = StringAlignment.Center;
                    e.Graphics.DrawString(e.Value.ToString(), base.Font, Brushes.White, e.CellBounds, sf);
                }

                e.Handled = true;
            }
        }

        private int m_nExtralColumn = 1;
        public int ExtralColumn
        {
            get { return m_nExtralColumn; }
            set { m_nExtralColumn = value; Invalidate(); }
        }

        private bool m_bDrawHorizon = true;
        [Description("是否绘制水分线")]
        public bool bDrawHorizon
        {
            get {return m_bDrawHorizon; }
            set { m_bDrawHorizon = value; Invalidate(); }
        }

        private bool m_bDrawVertical = false;
        [Description("是否绘制垂直线")]
        public bool bDrawVertical
        {
            get { return m_bDrawVertical; }
            set { m_bDrawVertical = value; Invalidate(); }
        }


        private int m_nExtralRow = 2;
        /// <summary>
        /// 绘制控件事件
        /// </summary>
        /// <param name="e"></param>
        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e); 
            //return;
            if (ColumnCount == 0) return;
            Graphics g = e.Graphics;
            Rectangle rcClient = ClientRectangle;

            bool bDrawHorizon = true; //绘制水平线
            bool bDrawVertical = false;

            using (Pen p = new Pen(GridColor))
            {
                int nColumnIndex = 0;
                if (RowHeadersVisible) nColumnIndex = -1;
                else
                    while (nColumnIndex < ColumnCount - 1 && !Columns[nColumnIndex].Visible)
                    {
                        nColumnIndex++;   //隐藏列
                    }

                if (m_bDrawHorizon)//水平线
                {
                    for (int i = 0; i <= RowCount && GetCellDisplayRectangle(nColumnIndex, i - 1, false).Bottom < rcClient.Bottom; i++)
                    {
                        Point ptStart = new Point(GetCellDisplayRectangle(nColumnIndex, i - 1, false).X, GetCellDisplayRectangle(nColumnIndex, i - 1, false).Bottom - 1);
                        Point ptStop = new Point(rcClient.Right - GetCellDisplayRectangle(nColumnIndex, i - 1, false).X, GetCellDisplayRectangle(nColumnIndex, i - 1, false).Bottom - 1);
                        g.DrawLine(p, ptStart, ptStop);
                    }

                    if (GetCellDisplayRectangle(nColumnIndex, RowCount - 1, false).Bottom != 0)
                    {
                        if (rcClient.Bottom > GetCellDisplayRectangle(nColumnIndex, RowCount - 1, false).Bottom &&
                            (!GetCellDisplayRectangle(nColumnIndex, RowCount - 1, false).IsEmpty && RowCount > 0 || RowCount == 0))
                        {
                            m_nExtralRow = (int)((rcClient.Bottom - GetCellDisplayRectangle(nColumnIndex, RowCount - 1, false).Bottom) * 1.0 / RowTemplate.Height);
                            if ((rcClient.Bottom - GetCellDisplayRectangle(nColumnIndex, RowCount - 1, false).Bottom % RowTemplate.Height) != 0)
                                m_nExtralRow++;

                            for (int i = 1; i < m_nExtralRow; i++)
                            {
                                Point ptStart = new Point(GetCellDisplayRectangle(nColumnIndex, RowCount - 1, false).X, GetCellDisplayRectangle(nColumnIndex, RowCount - 1, false).Bottom + i * RowTemplate.Height - 1);
                                Point ptStop = new Point(rcClient.Right - GetCellDisplayRectangle(nColumnIndex, RowCount - 1, false).X, GetCellDisplayRectangle(nColumnIndex, RowCount - 1, false).Bottom + i * RowTemplate.Height - 1);
                                g.DrawLine(p, ptStart, ptStop);
                            }
                        }
                    }
                }

                if (m_bDrawVertical)//垂直线
                {
                    for (int i = 0; i <= ColumnCount && GetCellDisplayRectangle(i - 1, -1, false).Right < rcClient.Right; i++)
                    {
                        Point ptStart = new Point((GetCellDisplayRectangle(i - 1, -1, false).Right) - 1, GetCellDisplayRectangle(nColumnIndex, -1, false).Top);
                        Point ptStop = new Point((GetCellDisplayRectangle(i - 1, -1, false).Right) - 1, rcClient.Bottom - GetCellDisplayRectangle(nColumnIndex, -1, false).Top);
                        g.DrawLine(p, ptStart, ptStop);
                    }

                    if (rcClient.Right > GetCellDisplayRectangle(ColumnCount - 1, -1, false).Right && !GetCellDisplayRectangle(ColumnCount - 1, -1, false).IsEmpty)
                    {
                        int nExtraWidth = (rcClient.Right - GetCellDisplayRectangle(ColumnCount - 1, -1, false).Right) / m_nExtralColumn;
                        for (int i = 1; i < m_nExtralColumn; i++)
                        {
                            Point ptStart = new Point(GetCellDisplayRectangle(ColumnCount - 1, -1, false).Right + i * nExtraWidth - 1, GetCellDisplayRectangle(nColumnIndex, -1, false).Top);
                            Point ptStop = new Point(GetCellDisplayRectangle(ColumnCount - 1, -1, false).Right + i * nExtraWidth - 1, rcClient.Bottom - GetCellDisplayRectangle(nColumnIndex, -1, false).Top);
                            g.DrawLine(p, ptStart, ptStop);
                        }
                    }
                }
            }
        }


    }