关于在读取excel的文件时候，放在服务器上就报路径错误

就是指定这个路径：C:\Program Files (x86)\IIS Express

因为在上传到服务器的时候，服务器读取的是在服务器上的路径，所以正确的思路应该是

把上传的Excel存在服务器上，再去读取服务器上的excel，这样就行了。

有个弊端就是，需要定期去清除存在服务器上的Excel。

  try
             {
                 string sheetname = TextBox1.Text.Trim();
                 if (string.IsNullOrEmpty(sheetname))
                 {
                     ShowAlertMessage("sheetname不可为空！");
                     return;
                 }
                 string username = Context.Items["UserName"].ToString();
                 HttpPostedFile upLoadPostFile = FileUpload1.PostedFile;
                 string upLoadPath = upLoadPostFile.FileName;
                 int upLoadPathLength = upLoadPath.Split('\\').Length;
                 string FileName = upLoadPath.Split('\\')[upLoadPathLength - ].ToString();

                 if (upLoadPath == "")
                 {
                     ShowAlertMessage("请选择上传文件！");
                     return;
                 }
                 string excelType = upLoadPath.Split('.')[].ToString();
                 if (excelType != "xls" && excelType != "xlsx")
                 {
                     ShowAlertMessage("此文件不是xls或者xlsx格式，请重新选择上传文件格式！");
                 }
                 else
                 {

                     DataSet ds = GetExcelData(upLoadPostFile, sheetname, FileName);
                     DataTable dtInfo = ds.Tables[];
                     for (int i = ; i < dtInfo.Rows.Count; i++)
                     {
                         string strOrderSn = dtInfo.Rows[i][].ToString();
                         if (string.IsNullOrEmpty(strOrderSn))
                         {
                             ShowAlertMessage("读取数据结束");
                         }
                         DataTable dtOrder = InvoiceData.GetOrderHead(strOrderSn).Tables[];
                         if (dtOrder.Rows.Count == )
                         {
                             throw new Exception("ChangeOrderStatusReturnGoods Error:订单不存在：" + strOrderSn + "");
                         }
                         string OrderStatus = dtOrder.Rows[]["OrderStatus"].ToString();
                         if (OrderStatus != "")
                         {
                             InvoiceData.UpdateStatusByReturnGoods(strOrderSn);
                             OrderData.OrderOperationLog(strOrderSn, username, DateTime.Now, "退货更改订单状态");
                         }
                     }
                 }
                 ShowAlertMessage("状态更改完毕！");
             }
             catch (Exception ex)
             {
                 CustomValidator1.ErrorMessage = ex.Message;
                 CustomValidator1.IsValid = false;
             }

  public static DataSet GetExcelData(HttpPostedFile upLoadPostFile, string sheetName, string FileName)
         {
             string strPath = ConfigurationManager.AppSettings.Get("ReturnGoodsUploadExcelPath").ToString();
             Directory.CreateDirectory(strPath);
             Guid guidnew = Guid.NewGuid();
             string NewPath = strPath + @"\" + DateTime.Now.ToString("yyyy-MM-dd")+"_"+""+guidnew.ToString()+"" + FileName;
             upLoadPostFile.SaveAs(NewPath);
             DataSet ds = InvoiceData.ExcelToDataSet(NewPath, "");
             return ds;
         }

  /// <summary>
         /// Excel转换成DataSet（.xlsx/.xls）
         /// </summary>
         /// <param name="filePath">Excel文件路径</param>
         /// <param name="strMsg"></param>
         /// <returns></returns>
         public static DataSet ExcelToDataSet(string filePath, string strMsg)
         {
             strMsg = "";
             DataSet ds = new DataSet();
             DataTable dt = new DataTable();
             string fileType = Path.GetExtension(filePath).ToLower();
             string fileName = Path.GetFileName(filePath).ToLower();
             try
             {
                 ISheet sheet = null;
                 int sheetNumber = ;
                 FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read);
                 if (fileType == ".xlsx")
                 {
                     // 2007版本
                     XSSFWorkbook workbook = new XSSFWorkbook(fs);
                     sheetNumber = workbook.NumberOfSheets;
                     for (int i = ; i < sheetNumber; i++)
                     {
                         string sheetName = workbook.GetSheetName(i);
                         sheet = workbook.GetSheet(sheetName);
                         if (sheet != null)
                         {
                             dt = GetSheetDataTable(sheet, strMsg);
                             if (dt != null)
                             {
                                 dt.TableName = sheetName.Trim();
                                 ds.Tables.Add(dt);
                             }
                             else
                             {
                                 MessageBox.Show("Sheet数据获取失败，原因：" + strMsg);
                             }
                         }
                     }
                 }
                 else if (fileType == ".xls")
                 {
                     // 2003版本
                     HSSFWorkbook workbook = new HSSFWorkbook(fs);
                     sheetNumber = workbook.NumberOfSheets;
                     for (int i = ; i < sheetNumber; i++)
                     {
                         string sheetName = workbook.GetSheetName(i);
                         sheet = workbook.GetSheet(sheetName);
                         if (sheet != null)
                         {
                             dt = GetSheetDataTable(sheet, strMsg);
                             if (dt != null)
                             {
                                 dt.TableName = sheetName.Trim();
                                 ds.Tables.Add(dt);
                             }
                             else
                             {
                                 MessageBox.Show("Sheet数据获取失败，原因：" + strMsg);
                             }
                         }
                     }
                 }
                 return ds;
             }
             catch (Exception ex)
             {
                 strMsg = ex.Message;
                 return null;
             }
         }
         /// <summary>
         /// 获取sheet表对应的DataTable
         /// </summary>
         /// <param name="sheet">Excel工作表</param>
         /// <param name="strMsg"></param>
         /// <returns></returns>
         public static DataTable GetSheetDataTable(ISheet sheet, string strMsg)
         {
             strMsg = "";
             DataTable dt = new DataTable();
             string sheetName = sheet.SheetName;
             int startIndex = ;// sheet.FirstRowNum;
             int lastIndex = sheet.LastRowNum;
             //最大列数
             int cellCount = ;
             IRow maxRow = sheet.GetRow();
             for (int i = startIndex; i <= lastIndex; i++)
             {
                 IRow row = sheet.GetRow(i);
                 if (row != null && cellCount < row.LastCellNum)
                 {
                     cellCount = row.LastCellNum;
                     maxRow = row;
                 }
             }
             //列名设置
             try
             {
                 for (int i = ; i < maxRow.LastCellNum; i++)//maxRow.FirstCellNum
                 {
                     dt.Columns.Add(Convert.ToChar(((int)'A') + i).ToString());
                     //DataColumn column = new DataColumn("Column" + (i + 1).ToString());
                     //dt.Columns.Add(column);
                 }
             }
             catch
             {
                 strMsg = "工作表" + sheetName + "中无数据";
                 return null;
             }
             //数据填充
             for (int i = startIndex; i <= lastIndex; i++)
             {
                 IRow row = sheet.GetRow(i);
                 DataRow drNew = dt.NewRow();
                 if (row != null)
                 {
                     for (int j = row.FirstCellNum; j < row.LastCellNum; ++j)
                     {
                         if (row.GetCell(j) != null)
                         {
                             ICell cell = row.GetCell(j);
                             switch (cell.CellType)
                             {
                                 case CellType.Blank:
                                     drNew[j] = "";
                                     break;
                                 case CellType.Numeric:
                                     short format = cell.CellStyle.DataFormat;
                                     //对时间格式（2015.12.5、2015/12/5、2015-12-5等）的处理
                                     if (format ==  || format ==  || format ==  || format == )
                                         drNew[j] = cell.DateCellValue;
                                     else
                                         drNew[j] = cell.NumericCellValue;
                                     if (cell.CellStyle.DataFormat ==  || cell.CellStyle.DataFormat ==  || cell.CellStyle.DataFormat == )
                                         drNew[j] = cell.NumericCellValue.ToString("#0.00");
                                     break;
                                 case CellType.String:
                                     drNew[j] = cell.StringCellValue;
                                     break;
                                 case CellType.Formula:
                                     try
                                     {
                                         drNew[j] = cell.NumericCellValue;
                                         if (cell.CellStyle.DataFormat ==  || cell.CellStyle.DataFormat ==  || cell.CellStyle.DataFormat == )
                                             drNew[j] = cell.NumericCellValue.ToString("#0.00");
                                     }
                                     catch
                                     {
                                         try
                                         {
                                             drNew[j] = cell.StringCellValue;
                                         }
                                         catch { }
                                     }
                                     break;
                                 default:
                                     drNew[j] = cell.StringCellValue;
                                     break;
                             }
                         }
                     }
                 }
                 dt.Rows.Add(drNew);
             }
             return dt;
         }