C#使用NPOI上传excel

using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;

 public DataTable GetexcelDataSet(string path, Stream fs)
  {
   IWorkbook workbook = null;
   if (path.IndexOf(".xlsx") > 0)
   {
    workbook = new XSSFWorkbook(fs);//excel的版本2007
   }
   else if (path.IndexOf(".xls") > 0)
   {
    workbook = new HSSFWorkbook(fs);//excel的版本2003
   }
   ISheet sheet = workbook.GetSheetAt(0);//得到第一张表
   DataTable table = new DataTable();
   IRow headerRow = sheet.GetRow(0);//第一行为标题行
   int cellCount = headerRow.LastCellNum;//LastCellNum = PhysicalNumberOfCells
   int rowCount = sheet.LastRowNum;//LastRowNum = PhysicalNumberOfRows - 1

   for (int i = headerRow.FirstCellNum; i < cellCount; i++)
   {
    DataColumn column = new DataColumn(headerRow.GetCell(i).StringCellValue);
    table.Columns.Add(column);//添加行标题
   }
   for (int i = (sheet.FirstRowNum + 1); i <= rowCount; i++)
   {
    IRow row = sheet.GetRow(i);
    DataRow dataRow = table.NewRow();
    if (row != null)
    {
     for (int j = row.FirstCellNum; j < cellCount; j++)
     {
      if (row.GetCell(j) != null)
       dataRow[j] = row.GetCell(j);

     }
    }
    table.Rows.Add(dataRow);
   }
   return table;
  }