How to create a password protected and encrypted excel file and decrypt it?

See more:

C#3.0

C#

ASP.NET

Dear all,

I am using below code snippet to download an excel file in our website.

but my problem is : I have to download a password protected and encrypted excel file and decrypt it using any windows based software.

please help me to solve this problem.

Any type of help is highly appreciable.

Thanks in advance.....

string strQuery = @"select
                   TSPR.Student_Code,
                   TSPR.Account_No,
                   isnull(TSED.Scholarship_Second,TSED.Scholarship_First) as [Amount],
                   (TSPR.First_Name+' '+TSPR.Middle_Name+' '+TSPR.Last_Name) as  [Name],
                   TSPR.Mobile,TDD.Disbursal_No As [Disbursal No],
                   TSPR.Bank_Name,
                   TSPR.IFSC_Code,
                   tdm.Dist_Name,
                   tBM.Block_Name,
                   TSM.School_Name
               from tbl_Disbursal_Details TDD
                   inner join tbl_Proposal_Detail TPD
                       on TPD.Proposal_No = SUBSTRING(Disbursal_No,19,4)+ '/' +SUBSTRING(Disbursal_No,3,10) + '/' +SUBSTRING(Disbursal_No,14,1)+ '/' +SUBSTRING(Disbursal_No,16,2) + '/' + SUBSTRING(Disbursal_No,24,2)
                   inner join tbl_Proposal_Master TPM
                       on TPM.Proposal_No = tpd.Proposal_No
                   inner join tbl_Student_Personal_Registration TSPR
                       on TSPR.Student_Code = TPM.Student_Code
                   inner join tbl_Student_Educational_Details TSED
                       on TSED.Student_Code = TSPR.Student_Code and TSED.School_Code = TSPR.School_Code
                   inner join tbl_Dist_Master TDM
                       on TDM.Dist_Code = SUBSTRING(TDD.Disbursal_No,5,2)
                   inner join tbl_Block_Master TBM
                       on TBM.Dist_Code = TDm.Dist_Code and TBM.Block_Code = SUBSTRING(TDD.Disbursal_No,7,2)
                   inner join tbl_School_Master TSM
                       on tsm.School_Code = SUBSTRING(TDD.Disbursal_No,3,10)
               where Disbursal_No = @DisNo And TPM.flag_Rejected_ByBank = 0 ";

           SqlCommand cmd = new SqlCommand(strQuery);
           cmd.Parameters.Add("@DisNo", SqlDbType.NVarChar).Value = DNo;
           DataTable dt = GetData(cmd);

           //Create a dummy GridView
           GridView GridView1 = new GridView();
           GridView1.AllowPaging = false;
           GridView1.DataSource = dt;
           GridView1.DataBind();

           Response.Clear();
           Response.Buffer = true;
           Response.AddHeader("content-disposition", "attachment;filename=" + DNo + ".xls");
           Response.Charset = "";
           Response.ContentType = "application/vnd.xls";
           StringWriter sw = new StringWriter();
           HtmlTextWriter hw = new HtmlTextWriter(sw);

           for (int i = 0; GridView1.Rows.Count; i++)
           {
               //Apply text style to each Row
               GridView1.Rows[i].Attributes.Add("class", "textmode");
           }

           GridView1.RenderControl(hw);

           //style to format numbers to string
           string style = @".textmode { mso-number-format:";
           Response.Write(style);
           Response.Output.Write(sw.ToString());
           Response.End();