修改TreeList单元格格式（实现类似单元格合并效果）

关键点：（1）TreeList中显示的单元格默认不显示上、下、左、右边框，显示的是TreeList自身的行横边框、列纵边框，具体对应TreeList属性中OptionView项下的ShowVertLines、ShowHorzLines两项，将其对应默认值由默认False改为True即可去除行横边框、列纵边框，然后设置怎样的单元格格式显示什么样的单元格格式；

　　　　（2）在*_CustomDrawNodeCell中修改函数，而不是*_NodeCellStyle中修改，另外需要注意，前者在后者前运行，因此后者中的修改会覆盖掉前者中的修改。

　　　　（3）绘制TreeList单元格网线时，自动会覆盖掉单元格的所有边框，这与WinForm中只需绘制右、下，不需要绘制左上边框不同。

　　

　　　　（4）如果只想汇总Treelist单元格边框，则不需要设置e.Hander = true;而如果想重绘单元格值或填充颜色则必须设置e.Hander = true;并且其值域不同，重绘的区域不同，即可以针对性重绘。

效果图如下：

举例：

(1)具体实现相关代码如下：

　

        private void tlPublic_CustomDrawNodeCell(object sender, DevExpress.XtraTreeList.CustomDrawNodeCellEventArgs e)
        {
            DataRow dr = e.Node.Tag as DataRow;
            if (dr != null)
            {
                Brush grid = new SolidBrush(Color.LightGray);//Color.Gray
                Pen gridPen = new Pen(grid);

                if (dr["PublicId"].ToString() == "-2")
                {
                    //e.Appearance.ForeColor = TrueLore.PBTool.BaseUI.DataGridViewComponent.GridViewSumRowFontColor;
                    e.Appearance.Font = new Font(this.Font, FontStyle.Bold);
                }
                else if (e.Node.HasChildren)
                {
                    Color parentCellBackColor = TrueLore.PBTool.BaseUI.DataGridViewComponent.TreeGridViewBidFileRowBackColor;
                    e.Cache.FillRectangle(parentCellBackColor,e.Bounds);
                    ////绘制值
                    e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y, e.Bounds.X + e.Bounds.Width, e.Bounds.Y);
                    e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                }
                else
                {
                    #region TreeList实现类似单元格合并的效果
                    //现在属性中OptionView项下将ShowHorzlines设置为True
                    //当绘制TreeList单元格时会覆盖掉单元格的上下左右边框，因为TreeList的列纵线被设置为显示，行横线被设置为不显示，所以只需绘制上下线即可。

                    bool isMergeCell = false;
                    string cellCaption = string.Empty;
                    foreach (string caption in colsHeaderText_H)
                    {
                        if (this.tlPublic.Columns[e.Column.AbsoluteIndex].Caption == caption) 
                        {
                            isMergeCell = true;
                            cellCaption = caption;
                            break;
                        }
                    }
                        //纵向合并
                    if (isMergeCell == true)   //this.tlPublic.Columns[e.Column.AbsoluteIndex].Caption == caption) //&& e.Node.NextNode != null
                        {
                            Brush cellBackBrush = new System.Drawing.SolidBrush(e.Appearance.BackColor);
                            if (e.Node.NextNode == null)
                            {
                                //下边缘的线
                                e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                            }
                            else if (e.Node.GetDisplayText(e.Column.AbsoluteIndex) != e.Node.NextNode.GetDisplayText(e.Column.AbsoluteIndex))
                            {
                                //下边缘的线
                                e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                            }
                            else
                            {
                                e.Graphics.FillRectangle(cellBackBrush, e.Bounds);
                                e.Handled = true;  //显示重绘（放置位置即值域不同，显示重绘的区域不同）
                            }
                            //首子节点绘制上边框，之所以放在代码最后是因为放在前面可能在单元格填充时覆盖掉
                            if (e.Node == e.Node.ParentNode.FirstNode)
                            {
                                e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y, e.Bounds.X + e.Bounds.Width, e.Bounds.Y);
                            }
                        }
                        //非合并列
                        else
                        {
                            //当绘制TreeList单元格时会覆盖掉单元格的上下左右边框，因为TreeList的列纵线被设置为显示，行横线被设置为不显示，所以只需绘制上下线即可。
                            e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y, e.Bounds.X + e.Bounds.Width, e.Bounds.Y);
                            e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                        }
                    #endregion
                }
            }

        }

 

 多加代码：

(2)具体实现相关代码如下：

        //需要(行、列)合并的所有列标题名
        List<String> colsHeaderText_H = new List<String>();

        private void InitFormatColumns()
        {
            colsHeaderText_H.Add("量化合计");
            colsHeaderText_H.Add("投标报价");
            colsHeaderText_H.Add("评标价");
        }

        private void tlPublic_CustomDrawNodeCell(object sender, DevExpress.XtraTreeList.CustomDrawNodeCellEventArgs e)
        {
            DataRow dr = e.Node.Tag as DataRow;
            if (dr != null)
            {
                Brush gridBrush = new SolidBrush(Color.Pink);
                Brush grid = new SolidBrush(Color.Gray);
                Pen gridPen = new Pen(grid);

                ////e.Graphics.FillRectangle(gridBrush, e.Bounds);
                //e.Cache.DrawRectangle(gridPen, e.Bounds);
                //下边缘的线
                //e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                ////绘制值
                //e.Graphics.DrawString(e.Node.GetDisplayText(e.Column.AbsoluteIndex), e.Appearance.Font,
                //        Brushes.Crimson, e.Bounds.X + 2, e.Bounds.Y + 2, StringFormat.GenericDefault);

                if (dr["PublicId"].ToString() == "-2")
                {
                    e.Appearance.ForeColor = TrueLore.PBTool.BaseUI.DataGridViewComponent.GridViewSumRowFontColor;
                    e.Appearance.Font = new Font(this.Font, FontStyle.Bold);

                    //e.Graphics.FillRectangle(gridBrush, e.Bounds);
                    //e.Cache.DrawRectangle(gridPen,e.Bounds);
                    //下边缘的线
                    //e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                    
                    ////绘制值
                    //e.Graphics.DrawString(e.Node.GetDisplayText(e.Column.AbsoluteIndex), e.Appearance.Font,
                    //        Brushes.Crimson, e.Bounds.X + 2, e.Bounds.Y + 2, StringFormat.GenericDefault);
                }
                else if (e.Node.HasChildren)
                {
                    //e.Appearance.BackColor = TrueLore.PBTool.BaseUI.DataGridViewComponent.TreeGridViewParentRowBackColor;
                    Color parentCellBackColor = TrueLore.PBTool.BaseUI.DataGridViewComponent.TreeGridViewParentRowBackColor;
                    //e.Cache.DrawRectangle(gridPen, e.Bounds);
                    e.Cache.FillRectangle(parentCellBackColor,e.Bounds);
                    ////绘制值
                    e.Graphics.DrawString(e.Node.GetDisplayText(e.Column.AbsoluteIndex), e.Appearance.Font,
                            Brushes.Crimson, e.Bounds.X + 2, e.Bounds.Y + 2, StringFormat.GenericDefault);//下边缘的线
                    e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                    
                    //e.Handled = true;
                    
                }
                else
                {
                    #region 注释代码
                    //string tmpCaption = e.Column.Caption;
                    //if ("量化合计" == tmpCaption || "投标报价" == tmpCaption || "评标价" == tmpCaption)
                    //{
                    //    e.Appearance.BorderColor = e.Appearance.BackColor;
                    //    e.Handled = true;
                    //}
                    //e.Node.TreeList.RefreshCell(e.Node, e.Column);
                    //e.Cache.DrawRectangle();
                    #endregion

                    #region TreeList实现类似单元格合并的效果
                    //现在属性中OptionView项下将ShowHorzlines设置为True
                    //当绘制TreeList单元格时会覆盖掉单元格的上下左右边框，因为TreeList的列纵线被设置为显示，行横线被设置为不显示，所以只需绘制上下线即可。

                    bool isMergeCell = false;
                    string cellCaption = string.Empty;
                    foreach (string caption in colsHeaderText_H)
                    {
                        if (this.tlPublic.Columns[e.Column.AbsoluteIndex].Caption == caption) 
                        {
                            isMergeCell = true;
                            cellCaption = caption;
                            break;
                        }
                    }
                        //纵向合并
                    if (isMergeCell == true)   //this.tlPublic.Columns[e.Column.AbsoluteIndex].Caption == caption) //&& e.Node.NextNode != null
                        {
                            Brush cellBackBrush = new System.Drawing.SolidBrush(e.Appearance.BackColor);

                            //若与下一单元格值不同
                            //if (e.CellValue.ToString() != e.Node.NextNode.GetDisplayText(e.Column.AbsoluteIndex))
                            if (e.Node.NextNode == null)
                            {
                                //e.Cache.DrawRectangle(gridPen, e.Bounds);
                                e.Graphics.FillRectangle(cellBackBrush, e.Bounds);
                                //e.Appearance.FillRectangle(e.Cache, e.Bounds);
                                //下边缘的线
                                e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                                //绘制值
                                e.Graphics.DrawString(e.Node.GetDisplayText(e.Column.AbsoluteIndex), e.Appearance.Font,
                                        Brushes.Crimson, e.Bounds.X + 2, e.Bounds.Y + 2, StringFormat.GenericDefault);
                            }
                            else if (e.Node.GetDisplayText(e.Column.AbsoluteIndex) != e.Node.NextNode.GetDisplayText(e.Column.AbsoluteIndex))
                            {
                                //e.Cache.DrawRectangle(gridPen, e.Bounds);
                                e.Graphics.FillRectangle(cellBackBrush, e.Bounds);
                                //e.Appearance.FillRectangle(e.Cache, e.Bounds);
                                //下边缘的线
                                //e.Graphics.DrawLine(gridPen, e.Bounds.Left, e.Bounds.Bottom - 1, e.Bounds.Right, e.Bounds.Bottom);
                                //e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                                //绘制值
                                e.Graphics.DrawString(e.Node.GetDisplayText(e.Column.AbsoluteIndex), e.Appearance.Font,
                                        Brushes.Crimson, e.Bounds.X + 2, e.Bounds.Y + 2, StringFormat.GenericDefault);
                            }
                            else
                            {
                                //e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                                //e.Appearance.FillRectangle(e.Cache, e.Bounds);
                                e.Graphics.FillRectangle(cellBackBrush, e.Bounds);
                            }

                            //break;
                        }
                        //非合并列
                        else
                        {
                            //e.Cache.DrawRectangle(gridPen, e.Bounds); 
                            //当绘制TreeList单元格时会覆盖掉单元格的上下左右边框，因为TreeList的列纵线被设置为显示，行横线被设置为不显示，所以只需绘制上下线即可。
                            e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y, e.Bounds.X + e.Bounds.Width, e.Bounds.Y);
                            //绘制值
                            e.Graphics.DrawString(e.Node.GetDisplayText(e.Column.AbsoluteIndex), e.Appearance.Font,
                                    Brushes.Crimson, e.Bounds.X + 2, e.Bounds.Y + 2, StringFormat.GenericDefault);
                            //e.Handled = true;
                            ////下边缘的线
                            e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                           
                        }


                        ////设置处理事件完成（关键点），只有设置为ture,才能显示出想要的结果。
                        //e.Handled = true;
                    #endregion

                    //}
                }
                

                //设置处理事件完成（关键点），只有设置为ture,才能显示出想要的结果。
                e.Handled = true;
                          
            }

        }
        #endregion


        private void tlPublic_NodeCellStyle(object sender, DevExpress.XtraTreeList.GetCustomNodeCellStyleEventArgs e)
        {
            //string tmpCaption = e.Column.Caption;
            //if ("量化合计" == tmpCaption || "投标报价" == tmpCaption || "评标价" == tmpCaption)
            //{
            //    e.Appearance.BorderColor = e.Appearance.BackColor;
            //    e.Appearance.ForeColor = Color.Red;
            //    e.Node.TreeList.OptionsView.ShowFocusedFrame = false;
            //e.Column.AppearanceCell.Options.UseBorderColor = true;
            //e.Column.AppearanceCell.BorderColor = Color.DeepPink;
            //}
            //e.Appearance.BackColor = TrueLore.PBTool.BaseUI.DataGridViewComponent.TreeGridViewParentRowBackColor;
        }

 

(3)不想覆盖已有单元格内容（选择性覆盖）：首选将数节点的纵向边框去掉，再则添加事件及代码如下：

        private void tlcBidEvalationPrice_CustomDrawNodeCell(object sender, DevExpress.XtraTreeList.CustomDrawNodeCellEventArgs e)
        {
           if (e.Node == null)
            {
                return;
            }

            DataRow dr = e.Node.Tag as DataRow;
            
                
           if (dr != null)
            {
                Brush grid = new SolidBrush(Color.LightGray);       //Color.Gray
                Pen gridPen = new Pen(grid);
                if (dr["PublicId"].ToString() == "-1")
                {
                    Color parentCellBackColor = TrueLore.PBTool.BaseUI.DataGridViewComponent.TreeGridViewBidFileRowBackColor;
                    e.Cache.FillRectangle(parentCellBackColor, e.Bounds);
                    e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y, e.Bounds.X + e.Bounds.Width, e.Bounds.Y);
                    
                    e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                }
                else if (dr["PublicId"].ToString() == "-2")
                {
                    //Color sumRowBackColor = TrueLore.PBTool.BaseUI.DataGridViewComponent.GridViewSumRowBackColor;
                    //e.Cache.FillRectangle(sumRowBackColor, e.Bounds);
                    //当绘制TreeList单元格时会覆盖掉单元格的上下左右边框，因为TreeList的列纵线被设置为显示，行横线被设置为不显示，所以只需绘制上下线即可。
                    e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y, e.Bounds.X + e.Bounds.Width, e.Bounds.Y);
                    
                    //下边缘的线
                    e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                }
                else
                {
                    #region TreeList实现类似单元格合并的效果
                    //现在属性中OptionView项下将ShowHorzlines设置为True
                    //当绘制TreeList单元格时会覆盖掉单元格的上下左右边框，因为TreeList的列纵线被设置为显示，行横线被设置为不显示，所以只需绘制上下线即可。

                    bool isMergeCell = false;
                    string cellCaption = string.Empty;
                    foreach (string caption in colsHeaderText_H)
                    {
                        if (this.tlcBidEvalationPrice.Columns[e.Column.AbsoluteIndex].Caption == caption)
                        {
                            isMergeCell = true;
                            cellCaption = caption;
                            break;
                        }
                    }
                    //纵向合并
                    if (isMergeCell == true)   
                    {
                        Brush cellBackBrush = new System.Drawing.SolidBrush(e.Appearance.BackColor);

                        //若与下一单元格值不同
                        if (e.Node.NextNode == null )//|| e.Node.NextNode.NextNode == null
                        {
                            e.Graphics.FillRectangle(cellBackBrush, e.Bounds);
                            //当绘制TreeList单元格时会覆盖掉单元格的上下左右边框，因为TreeList的列纵线被设置为显示，行横线被设置为不显示，所以只需绘制上下线即可。
                            e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y, e.Bounds.X + e.Bounds.Width, e.Bounds.Y);
                            //下边缘的线
                            e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                            //绘制值
                            e.Graphics.DrawString(e.Node.GetDisplayText(e.Column.AbsoluteIndex), e.Appearance.Font,
                                    Brushes.Black, e.Bounds.X, e.Bounds.Y, StringFormat.GenericTypographic);
                        }
                        else if (e.Node.GetDisplayText(e.Column.AbsoluteIndex) != e.Node.NextNode.GetDisplayText(e.Column.AbsoluteIndex))
                        {
                            e.Graphics.FillRectangle(cellBackBrush, e.Bounds);
                        }
                        else
                        {
                            e.Graphics.FillRectangle(cellBackBrush, e.Bounds);
                        }
                    }
                    //非合并列
                    else
                    {
                        //当绘制TreeList单元格时会覆盖掉单元格的上下左右边框，因为TreeList的列纵线被设置为显示，行横线被设置为不显示，所以只需绘制上下线即可。
                        e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y, e.Bounds.X + e.Bounds.Width, e.Bounds.Y);
                       
                        //下边缘的线
                        e.Graphics.DrawLine(gridPen, e.Bounds.X, e.Bounds.Y + e.Bounds.Height, e.Bounds.X + e.Bounds.Width, e.Bounds.Y + e.Bounds.Height);
                    }
                    #endregion

                }

                //设置处理事件完成（关键点），只有设置为ture,才能显示出想要的结果。
                //e.Handled = true;		//不想覆盖已有内容就注掉（只绘制边框）

            }

        }