ProofRecords.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;

namespace HospitalsDashboard
{
    public partial class ProofRecords : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                this.bindgrid();


            }
        }

        private void bindgrid()
        {
            string constr = ConfigurationManager.ConnectionStrings["con"].ConnectionString;
            using (SqlConnection con = new SqlConnection(constr))
            {
                using (SqlCommand cmd = new SqlCommand())
                {
                    cmd.CommandText = "SELECT appointmentid,patientid,proofname,proofcontent,proofdata,datecreated FROM dbo.ProofRecords";
                    cmd.Connection = con;
                    con.Open();
                    GridView1.DataSource = cmd.ExecuteReader();
                    GridView1.DataBind();
                    con.Close();
                }
            }
        }

        protected void DownloadFile(object sender, EventArgs e)
        {
            int id = int.Parse((sender as LinkButton).CommandArgument);
            byte[] bytes;
            string fileName, contentType;
            string constr = ConfigurationManager.ConnectionStrings["con"].ConnectionString;
            using (SqlConnection con = new SqlConnection(constr))
            {
                using (SqlCommand cmd = new SqlCommand())
                {
                    cmd.CommandText = "select proofname, proofdata, proofcontent from dbo.ProofRecords where appointmentid=@Id";
                    cmd.Parameters.AddWithValue("@Id", id);
                    cmd.Connection = con;
                    con.Open();
                    using (SqlDataReader sdr = cmd.ExecuteReader())
                    {
                        sdr.Read();
                        // var s = sdr.GetByte(3);
                        // bytes =(byte[])(sdr["proofdata"]);
                        bytes = System.Text.Encoding.Unicode.GetBytes(sdr["proofdata"].ToString());
                        contentType = sdr["proofcontent"].ToString();
                        fileName = sdr["proofname"].ToString();
                    }
                    con.Close();
                }
            }
            Response.Clear();
            Response.Buffer = true;
            Response.Charset = "";
            Response.Cache.SetCacheability(HttpCacheability.NoCache);
            Response.ContentType = contentType;
            Response.AppendHeader("Content-Disposition", "attachment; filename=" + fileName);
            Response.BinaryWrite(bytes);
            Response.Flush();
            Response.End();
        }

    }
    }