Show PDf and ZIP files in products Nop1.2, I need to update to 2.4

Hi, I heve nopcommerce 1.2 and i want to update to 2.4, but the only thing that i can't update is .cs file that i have in 1.2 that let me add a pdf or zip file to a product automaticly if i save it in a directory whit the same name as the product. If anyone can do it it will be great as I see a lot of people in this forum looking for a pdf in the product page.

This is the code of the file in 1.2:

using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Configuration;
using System.Data;
using System.Text;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using NopSolutions.NopCommerce.Common;
using NopSolutions.NopCommerce.Common.Audit;
using NopSolutions.NopCommerce.Common.Configuration.Settings;
using NopSolutions.NopCommerce.Common.Localization;
using NopSolutions.NopCommerce.Common.Media;
using NopSolutions.NopCommerce.Common.Orders;
using NopSolutions.NopCommerce.Common.Products;
using NopSolutions.NopCommerce.Common.Utils;

namespace NopSolutions.NopCommerce.Web.Modules
{
    public partial class ProductFileDownload : System.Web.UI.UserControl
    {
        private string m_sCodProd = String.Empty;

        protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                BindData();
                LoadFiles();
            }
        }

        protected void BindData()
        {
            Product product = ProductManager.GetProductByID(ProductID);
            if (product != null)
            {
                m_sCodProd = product.Name;
            }
            else
                this.Visible = false;
        }

        protected void LoadFiles()
        {
            string m_sURL = URL();

            string URLds = m_sURL + "DS_" + m_sCodProd + ".PDF";
            string URLmn =  m_sURL + "MN_" + m_sCodProd + ".PDF";
            string URLzip = m_sURL + m_sCodProd + ".zip";

            if (System.IO.File.Exists(URLds))
            {
                trDS.Visible = true;
            }
            else
            {
                trDS.Visible = false;
            }
            if (System.IO.File.Exists(URLmn))
            {
                trMN.Visible = true;
            }
            else
            {
                trMN.Visible = false;
            }
            if (System.IO.File.Exists(URLzip))
            {
                trDW.Visible = true;
            }
            else
            {
                trDW.Visible = false;
            }

        }


        protected void DownloadFile(
            string strFileURL,
            string strFileName
            )
        {
            try
            {
                System.Net.WebClient web = new System.Net.WebClient();
                Byte[] buffer;

                buffer = web.DownloadData(strFileURL + strFileName);

                Response.ContentType = "application/x-zip-compressed";
                Response.AddHeader("content-disposition", "attachment;filename=" + strFileName);
                Response.AddHeader("content-length", buffer.Length.ToString());
                Response.BinaryWrite(buffer);
                Response.Flush();
            }
            catch
            {

            }

        }

        protected void OpenPDF(string URL)
        {
            try
            {
                Response.Clear();
                Response.ClearContent();
                Response.ClearHeaders();
                Response.ContentType = "application/pdf";
                Response.TransmitFile(URL);
                Response.End();
            }
            catch
            {

            }
        }

        protected void lnkDS_Click(object sender, EventArgs e)
        {
            BindData();
            string m_sURL = URL();
            string URLds = m_sURL + "DS_" + m_sCodProd + ".PDF";
            OpenPDF(URLds);
        }

        protected void lnkMN_Click(object sender, EventArgs e)
        {
            BindData();
            string m_sURL = URL();
            string URLmn = m_sURL + "MN_" + m_sCodProd + ".PDF";
            OpenPDF(URLmn);
        }

        protected void lnkDw_Click(object sender, EventArgs e)
        {
            BindData();
            string m_sURL = URL();
            string Filezip = m_sCodProd + ".zip";
            DownloadFile(m_sURL, Filezip);
        }

        public int ProductID
        {
            get
            {
                return CommonHelper.QueryStringInt("ProductID");
            }
        }

        protected string URL()
        {
            string sURL = "";
            System.Configuration.Configuration config = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("~");

            if (config.AppSettings.Settings.Count > 0)
            {
                KeyValueConfigurationElement element = config.AppSettings.Settings["DownloadFiles"];
                if (element != null)
                {
                    sURL = element.Value;
                }
            }

            if (System.IO.Directory.Exists(sURL))
            {
                return sURL;
            }
            else
            {
                return Server.MapPath("/Download-Files/");
            }

        }
    }

}