public static DataTable ReadDataFromExcelByNPOI()
{DataTable dt = new DataTable();var filePathAndName = Path.Combine(Server.MapPath("~/Content/Excel"), "ExcelForUploadTest.xls");//打开文件读取数据stream = System.IO.File.Open(filePathAndName2, FileMode.Open);    //通过Stream创建WorkbookHSSFWorkbook workbook = new HSSFWorkbook(stream);//获取excel的第一个sheetHSSFSheet sheet = (HSSFSheet)workbook.GetSheetAt(0);//设置隐藏列 为 不隐藏for (int iHide = 0; iHide <= 40; iHide++) {sheet.SetColumnHidden(iHide, false);}    //最后一列的标号(即总的行数)int rowCount = sheet.LastRowNum;//获取sheet的首行HSSFRow headerRow = (HSSFRow)sheet.GetRow(0);//一行最后一个方格的编号(即总的列数)int cellCount = headerRow.LastCellNum;string columnNames = @"A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,AA,AB,AC,AD,AE,AF,AG,AH,AI,AJ,AK,AL,AM,AN,AO,AP,AQ,AR,AS,AT,AU,AV,AW,AX,AY,AZ";string[] columns = columnNames.Split(',');//使用 A B C D ... 字母的方式 命名DataTable的各列名for (int i = headerRow.FirstCellNum; i < cellCount; i++){        //DataColumn column = new DataColumn(headerRow.GetCell(i).StringCellValue);DataColumn column = new DataColumn(columns[i]);dt.Columns.Add(column);}for (int i = (iHeaderRowIndex.Value + 1); i <= rowCount; i++){                        HSSFRow row = (HSSFRow)sheet.GetRow(i);DataRow dataRow = dt.NewRow();if (row != null){for (int j = row.FirstCellNum; j < cellCount; j++){if (row.GetCell(j) != null){//如果是公式Cell //则仅读取其Cell单元格的显示值 而不是读取公式if (row.GetCell(j).CellType == CellType.FORMULA){dataRow[j] = row.GetCell(j).StringCellValue;}else{dataRow[j] = row.GetCell(j).ToString();}}}}//某标示列 33//某标示列 38//其值非空 标示是有效数据//其值为空 标示结束if(string.IsNullOrEmpty(dataRow[33].ToString())&& string.IsNullOrEmpty(dataRow[38].ToString())){break;//读取结束 退出For循环
        }else{dt.Rows.Add(dataRow);}}workbook = null;sheet = null;return dt;
}#endregion