递归查询树，并绑定到界面控件

1、环境：VS2013 SQL Server2012

2、数据库脚本： 

with CTE as    
(     
-->Begin 一个定位点成员     
 select Id,MenuName,ParentId,cast(MenuName as nvarchar(max)) as TE,OrderNum,
                --ROW_NUMBER()over(order by getdate()) as OrderID
                CAST( (CASE 
                WHEN OrderNum < 10 THEN '00'+LTRIM(OrderNum)
                ELSE '0'+LTRIM(OrderNum)
                END) AS VARCHAR(100)) AS numstr 
        --最关键是上面这个字段，要获取排序字段，按字符串来排序。  
        --其中窗口函数必须要使用order by，但是不能用整型，那就用时间吧  
        from Main_Menu where ParentId = 0 
-->End      
union all     
-->Begin一个递归成员     
 select Main_Menu.ID, Main_Menu.MenuName,Main_Menu.ParentId,cast(replicate(' ',len(CTE.TE))+'|_'+Main_Menu.MenuName as nvarchar(MAX)) as TE,Main_Menu.OrderNum,  
        --CTE.OrderNum*100+Main_Menu.OrderNum as OrderNum
                --Main_Menu.OrderNum
                CAST( (CTE.numstr+
                CASE 
                WHEN Main_Menu.OrderNum < 10 THEN '00'+LTRIM(Main_Menu.OrderNum)
                ELSE '0'+LTRIM(Main_Menu.OrderNum)
                END) AS VARCHAR(100) ) AS numstr 
        from Main_Menu inner join CTE     
        on Main_Menu.ParentId=CTE.Id    
-->End     
)     
select * from CTE  
order by LTRIM(numstr) --最后将这个整型数据转换为字符串型的进行排序

3、C#代码：

public class readexcel
    {
        #region Excel2003
        /// <summary>
        /// 将Excel文件中的数据读出到DataTable中(xls)
        /// </summary>
        /// <param name="file"></param>
        /// <returns></returns>
        public static DataTable ExcelToTableForXLS(string file)
        {
            DataTable dt = new DataTable();
            using (FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read))
            {
                HSSFWorkbook hssfworkbook = new HSSFWorkbook(fs);
                ISheet sheet = hssfworkbook.GetSheetAt(0);

                //表头
                IRow header = sheet.GetRow(sheet.FirstRowNum);
                List<int> columns = new List<int>();
                for (int i = 0; i < header.LastCellNum; i++)
                {
                    object obj = GetValueTypeForXLS(header.GetCell(i) as HSSFCell);
                    if (obj == null || obj.ToString() == string.Empty)
                    {
                        dt.Columns.Add(new DataColumn("Columns" + i.ToString()));
                        //continue;
                    }
                    else
                        dt.Columns.Add(new DataColumn(obj.ToString()));
                    columns.Add(i);
                }
                //数据
                for (int i = sheet.FirstRowNum + 1; i <= sheet.LastRowNum; i++)
                {
                    DataRow dr = dt.NewRow();
                    bool hasValue = false;
                    foreach (int j in columns)
                    {
                        if (sheet.GetRow(i)==null)
                        {
                            continue;
                        }
                        dr[j] = GetValueTypeForXLS(sheet.GetRow(i).GetCell(j) as HSSFCell);
                        if (dr[j] != null && dr[j].ToString() != string.Empty)
                        {
                            hasValue = true;
                        }
                    }
                    if (hasValue)
                    {
                        dt.Rows.Add(dr);
                    }
                }
            }
            return dt;
        }

        /// <summary>
        /// 将DataTable数据导出到Excel文件中(xls)
        /// </summary>
        /// <param name="dt"></param>
        /// <param name="file"></param>
        public static void TableToExcelForXLS(DataTable dt, string file)
        {
            HSSFWorkbook hssfworkbook = new HSSFWorkbook();
            ISheet sheet = hssfworkbook.CreateSheet("Test");

            //表头
            IRow row = sheet.CreateRow(0);
            for (int i = 0; i < dt.Columns.Count; i++)
            {
                ICell cell = row.CreateCell(i);
                cell.SetCellValue(dt.Columns[i].ColumnName);
            }

            //数据
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                IRow row1 = sheet.CreateRow(i + 1);
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    ICell cell = row1.CreateCell(j);
                    cell.SetCellValue(dt.Rows[i][j].ToString());
                }
            }

            //转为字节数组
            MemoryStream stream = new MemoryStream();
            hssfworkbook.Write(stream);
            var buf = stream.ToArray();

            //保存为Excel文件
            using (FileStream fs = new FileStream(file, FileMode.Create, FileAccess.Write))
            {
                fs.Write(buf, 0, buf.Length);
                fs.Flush();
            }
        }

        /// <summary>
        /// 获取单元格类型(xls)
        /// </summary>
        /// <param name="cell"></param>
        /// <returns></returns>
        private static object GetValueTypeForXLS(HSSFCell cell)
        {
            if (cell == null)
                return null;
            switch (cell.CellType)
            {
                case CellType.Blank: //BLANK:
                    return null;
                case CellType.Boolean: //BOOLEAN:
                    return cell.BooleanCellValue;
                case CellType.Numeric: //NUMERIC:
                    return cell.NumericCellValue;
                case CellType.String: //STRING:
                    return cell.StringCellValue;
                case CellType.Error: //ERROR:
                    return cell.ErrorCellValue;
                case CellType.Formula: //FORMULA:
                default:
                    return "=" + cell.CellFormula;
            }
        }
        #endregion
    }