NPOI操作Excel导入DataTable中

using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using System.Data;
using System.IO;
using NPOI.XSSF.UserModel;

    刚刚接触Excel导入导出，感觉用NPOI蛮方便的就研究了一下，下面是Excel导入读取到DataTable中的功能
    #region
    public DataTable ImportExcel(string filePath)
    {
        using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read))
        {
            try
            {
                hssfworkbook = new XSSFWorkbook(file);
            }
            catch (Exception ex)
            {
                hssfworkbook = new HSSFWorkbook(file);
            }
        }
        ISheet sheet = hssfworkbook.GetSheetAt(0);
        System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
        DataTable dt = new DataTable();
        //获取列数,填充到DataTable中
        for (int j = 0; j < (sheet.GetRow(0).LastCellNum); j++)
        {
            dt.Columns.Add("列" + j);
        }
        //读取集合元素，递进读取
        while (rows.MoveNext())
        {
            IRow row = (IRow)rows.Current;
            DataRow dr = dt.NewRow();
            for (int i = 0; i < row.LastCellNum; i++)
            {
                ICell cell = row.GetCell(i);
                if (cell == null)
                {
                    dr[i] = null;
                }
                else
                {
                    dr[i] = cell.ToString();
                }
            }
            dt.Rows.Add(dr);
        }
        return dt;
    }
    #endregion

    在操作的时候有时候会出现“The supplied data appears to be in the Office 2007+ XML. POI only supports OLE2 Office documents ”错误，这是因为XSSFWorkbook支持.xlsx 2007格式，HSSFWorkbook 支持.xls 2003格式