ASP.NET中上傳EXCEL檔案一個比較快的方法

public string SaveUploadExcel(HttpPostedFile hpf)//驗證Excel檔案的正確性
  {
       //檢查檔案格式各檔案大小是否有效
       if(hpf == null || hpf.ContentLength < 1 || System.IO.Path.GetExtension(hpf.FileName).ToLower() != ".xls")
       {
            throw new InnerException("檔案上傳失敗或檔案格式不正確。！");
       }

       //儲存檔案
       try
       {
            string fileFullName = MakeFileName();
            hpf.SaveAs(fileFullName);
            return fileFullName;
       }
       catch//(Exception ex)
       {
            throw new InnerException("儲存檔案失敗。");// + ex.Message);
       }
  }

  public string MakeFileName()//產生唯一檔案名的Excel檔案
  {
       string filePath = HttpContext.Current.Server.MapPath(HttpContext.Current.Request.ApplicationPath)         +"\\uploadFiles\\PlanExcel";
       if(!Directory .Exists(filePath))
            Directory.CreateDirectory(filePath);
       string fileName = Convert.ToString(HttpContext.Current.Session["UserID"])  + "_"
        + DateTime.Now.ToString("yyyyMMddHHmmss")
        + ".xls";

       return filePath + "\\" + fileName;
  }

public DataTable ReadNoHeadExcelData(string fileFullName)//讀取Excel檔案最後返回一個DataTable，可以在返回DataTable後對這個DataTable進行檢驗！
  {
        string excelNoHeadConnStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=\"Excel 8.0;HDR=NO;IMEX=1;\"";//連接字串
       OleDbConnection oleCn =new OleDbConnection();
       try
       {
            string currConnStr = string.Format(excelNoHeadConnStr, fileFullName);//連接字串
            oleCn.ConnectionString = currConnStr;                    
            DataTable dt = new DataTable();
            oleCn.Open();
            string excelBookName = oleCn.GetOleDbSchemaTable(System.Data.OleDb.OleDbSchemaGuid.Tables, null).Rows[0][2].ToString();
            if(excelBookName!=string.Empty && excelBookName.Trim()!="")
            {
                 string currSqlStr = string.Format(excelSqlStr, excelBookName);//sql字串
                 OleDbCommand oleCmd = new OleDbCommand(currSqlStr, oleCn);
                 OleDbDataAdapter oleDda = new OleDbDataAdapter(oleCmd);
                 oleDda.Fill(dt);               
            }
            oleCn.Close();                
            return dt;
       }
       catch
       {
            string errorMsg="Excel檔案格式不對,請嘗試用excel開啟該檔案檢查內容並另存一下,確保成為正確的excel檔案,再重新上傳";
            System.Web.HttpContext.Current.Response.Write("<script>alert('"+ errorMsg  +"')</script>");
            oleCn.Close(); 
            return null;
        }
  }