Upload and Download Files in ASP.Net C#

protected void btnSave_Click(object sender, EventArgs e)

    {

       

string fname = Path.GetFileName(flupUpload.PostedFile.FileName.ToString());

string ext = Path.GetExtension(fname);  // to get extension of file

       

if (flupUpload.HasFile)

  {

flupUpload.SaveAs(Server.MapPath("fileCollection/" + fname));

string ins = "insert into tbl_upload(file_caption,file_name)values('" + txtcaption.Text + "','" + fname + "')";

obj.execute_Query(ins);

 }

       

}

    protected void btnShow_Click(object sender, EventArgs e)

    {

        string sel = "select * from tbl_upload";

        obj.fillGrid(grdFiles, sel);

    }

    protected void grdFiles_RowCommand(object sender, GridViewCommandEventArgs e)

    {

        if (e.CommandName == "download")

        {

            int id = Convert.ToInt32(e.CommandArgument.ToString());

            string str = "select * from tbl_upload where file_id=" + id + "";

            DataTable dt = new DataTable();

            dt = obj.select_Query(str);

            if (dt.Rows.Count > 0)

            {

                string name = dt.Rows[0]["file_name"].ToString();

               

    filedownload(name);

            }

        }

    }

protected void filedownload(string name)

 {

         Response.AppendHeader("content-disposition","attachment;filename=" + name + "");

        Response.TransmitFile(Server.MapPath("fileCollection/" + name));

        Response.End();

    }

}