ExcellHelper 帮助类 2007和2003 任意转换

最近 的一些excel的，命名不规范。多选 类型

fileDialog.Filter = "所有文档(*.doc;*.docx)|*.doc;*.docx|所有文件(*.*)|*.*";

所以改进了一下这个类

using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Text;

namespace NPOI.EXCELL
{
    public class Excell
    {
        public DataTable ExcelsToDataTable(string filepath, string sheetname, bool isFirstRowColumn)
        {
           return ExcelToDataTable( filepath,  sheetname,  isFirstRowColumn);
        }
        public int DataTableToExcels(DataTable data, string filepath, string sheename, bool iscolumwrite)
        {
            return DataTableToExcel(data,filepath, sheename, iscolumwrite);
        }
        /// <summary>
        /// 将Excel导入DataTable
        /// </summary>
        /// <param name="filepath">导入的文件路径（包括文件名）</param>
        /// <param name="sheetname">工作表名称</param>
        /// <param name="isFirstRowColumn">第一行是否是DataTable的列名</param>
        /// <returns>DataTable</returns>
        public DataTable ExcelToDataTable(string filepath, string sheetname, bool isFirstRowColumn)
        {
            ISheet sheet = null;//工作表
            DataTable data = new DataTable();
            FileStream fs;
            IWorkbook workbook = null;
            var startrow = 0;
            using (fs = new FileStream(filepath, FileMode.Open, FileAccess.Read))
            {
                try
                {
             
                 
                    try
                    {
                        if (filepath.IndexOf(".xlsx") > 0) // 2007版本
                            workbook = new XSSFWorkbook(fs);
                        else if (filepath.IndexOf(".xls") > 0) // 2003版本
                            workbook = new HSSFWorkbook(fs);
                    }
                    catch
                    {
                    }

                    try
                    {
                        if (workbook == null)
                        {
                            using (fs = new FileStream(filepath, FileMode.Open, FileAccess.Read)) { 
                                workbook = new XSSFWorkbook(fs);
                            }
                        }
                    }
                    catch { 
                    }
                    try
                    {
                        if (workbook == null)
                        {
                            using (fs = new FileStream(filepath, FileMode.Open, FileAccess.Read))
                            {
                                workbook = new HSSFWorkbook(fs);
                            }
                        }
                    }
                    catch {
                    }


                    if (sheetname != null)
                    {
                        sheet = workbook.GetSheet(sheetname);
                        if (sheet == null) //如果没有找到指定的sheetName对应的sheet，则尝试获取第一个sheet
                        {
                            sheet = workbook.GetSheetAt(0);
                        }
                    }
                    else
                    {
                        sheet = workbook.GetSheetAt(0);
                    }
                    if (sheet != null)
                    {
                        IRow firstrow = sheet.GetRow(0);
                        int cellCount = firstrow.LastCellNum; //行最后一个cell的编号 即总的列数
                        if (isFirstRowColumn)
                        {
                            for (int i = firstrow.FirstCellNum; i < cellCount; i++)
                            {
                                ICell cell = firstrow.GetCell(i);
                                if (cell != null)
                                {
                                    string cellvalue = cell.StringCellValue;
                                    if (cellvalue != null)
                                    {
                                        DataColumn column = new DataColumn(cellvalue);
                                        data.Columns.Add(column);
                                    }
                                }
                            }
                            startrow = sheet.FirstRowNum + 1;
                        }
                        else
                        {
                            startrow = sheet.FirstRowNum;
                        }
                        //读数据行
                        int rowcount = sheet.LastRowNum;
                        for (int i = startrow; i < rowcount; i++)
                        {
                            IRow row = sheet.GetRow(i);
                            if (row == null)
                            {
                                continue; //没有数据的行默认是null
                            }
                            DataRow datarow = data.NewRow();//具有相同架构的行
                            for (int j = row.FirstCellNum; j < cellCount; j++)
                            {
                                if (row.GetCell(j) != null)
                                {
                                    datarow[j] = row.GetCell(j).ToString();
                                }
                            }
                            data.Rows.Add(datarow);
                        }
                    }
                    return data;
                }
                catch (Exception ex)
                {
                    Console.WriteLine("Exception: " + ex.Message);
                    return null;
                }
                finally { fs.Close(); fs.Dispose(); }
            }
        }

        /// <summary>
        /// 将DataTable导入到Excel
        /// </summary>
        /// <param name="data">要导入的数据</param>
        /// <param name="filepath">导入的文件路径（包含文件名称）</param>
        /// <param name="sheename">要导入的表名</param>
        /// <param name="iscolumwrite">是否写入列名</param>
        /// <returns>导入Excel的行数</returns>
        public int DataTableToExcel(DataTable data, string filepath, string sheename, bool iscolumwrite)
        {
            int i = 0;
            int j = 0;
            int count = 0;
            FileStream fs;
            IWorkbook workbook=null;
            ISheet sheet = null;
            using (fs = new FileStream(filepath, FileMode.OpenOrCreate, FileAccess.ReadWrite))
            {
                //根据Excel不同版本实例不同工作铺
                if (filepath.IndexOf(".xlsx") > 0) // 2007版本
                {
                    workbook = new XSSFWorkbook();
                }
                else if (filepath.IndexOf(".xls") > 0) // 2003版本
                    workbook = new HSSFWorkbook();

                try
                {
                    if (workbook != null)
                    {
                        sheet = workbook.CreateSheet(sheename);
                    }
                    else
                    {
                        return -1;
                    }

                    if (iscolumwrite == true) //写入DataTable的列名
                    {
                        IRow row = sheet.CreateRow(0);
                        for (j = 0; j < data.Columns.Count; ++j)
                        {
                            row.CreateCell(j).SetCellValue(data.Columns[j].ColumnName);
                        }
                        count = 1;
                    }
                    else
                    {
                        count = 0;
                    }

                    for (i = 0; i < data.Rows.Count; ++i)
                    {
                        IRow row = sheet.CreateRow(count);
                        for (j = 0; j < data.Columns.Count; ++j)
                        {
                            row.CreateCell(j).SetCellValue(data.Rows[i][j].ToString());
                        }
                        count++;
                    }
                    workbook.Write(fs); //写入到excel
                    return count;
                }
                catch (Exception ex)
                {
                    Console.WriteLine("Exception: " + ex.Message);
                    return -1;
                }
                finally { fs.Close(); fs.Dispose(); }
            }
        }


    }
}

Excell h = new Excell();
DataTable de = h.ExcelsToDataTable(@"a0016.xls", "Sheet1", true);

//a0016.xls 这个实际是 2007 的 导致了代码报错