File Download

To download a file
1. Create a new aspx page and code as follows


//TEST.ASPX
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="TestFileDownload.aspx.cs" Inherits="TESTUI.TestFileDownload" %>


//TEST.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.Net;
using System.IO;
using System.Threading;

namespace TestUI
{
    public partial class TestFileDownload: System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            string FileId = Request.QueryString["FileID"].ToString();
            string FileName = Request.QueryString["FileName"].ToString();
             
            string path = Server.MapPath( "~/files/" + FileId + "/" + FileName);

            fileDownload(FileName, path);

        }

        private void fileDownload(string fileName, string fileUrl)
        {
            Page.Response.Clear();
            bool success = ResponseFile(Page.Request, Page.Response, fileName, fileUrl, 1024000);
            if (!success)
                Response.Write("Downloading Error!");
            Page.Response.End();

        }
        public static bool ResponseFile(HttpRequest _Request, HttpResponse _Response, string _fileName, string _fullPath, long _speed)
        {
            try
            {
                FileStream myFile = new FileStream(_fullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
                BinaryReader br = new BinaryReader(myFile);
                try
                {
                    _Response.AddHeader("Accept-Ranges", "bytes");
                    _Response.Buffer = false;
                    long fileLength = myFile.Length;
                    long startBytes = 0;

                    int pack = 10240; //10K bytes
                    int sleep = (int)Math.Floor((double)(1000 * pack / _speed)) + 1;
                    if (_Request.Headers["Range"] != null)
                    {
                        _Response.StatusCode = 206;
                        string[] range = _Request.Headers["Range"].Split(new char[] { '=', '-' });
                        startBytes = Convert.ToInt64(range[1]);
                    }
                    _Response.AddHeader("Content-Length", (fileLength - startBytes).ToString());
                    if (startBytes != 0)
                    {
                        _Response.AddHeader("Content-Range", string.Format(" bytes {0}-{1}/{2}", startBytes, fileLength - 1, fileLength));
                    }
                    _Response.AddHeader("Connection", "Keep-Alive");
                 
                    _Response.ContentType = "application/octet-stream";
                    _Response.ClearContent();
                    _fileName = _fileName.Replace(" ", "");
                    _Response.AddHeader("Content-Disposition", "attachment;filename=" + _fileName);

                    br.BaseStream.Seek(startBytes, SeekOrigin.Begin);
                    int maxCount = (int)Math.Floor((double)((fileLength - startBytes) / pack)) + 1;

                    for (int i = 0; i < maxCount; i++)
                    {
                        if (_Response.IsClientConnected)
                        {
                            _Response.BinaryWrite(br.ReadBytes(pack));
                            Thread.Sleep(sleep);
                        }
                        else
                        {
                            i = maxCount;
                        }
                    }
                }
                catch
                {
                    return false;
                }
                finally
                {
                    br.Close();
                    myFile.Close();
                }
            }
            catch
            {
                return false;
            }
            return true;
        }
    }
}



2. Pass Parameters ie FileID and FileName to download

var FileID = 1;
var  FileName = "TestFileName";
 FileName = FileName.replace(/&/g, "%26");

window.open('../TestFileDownload.aspx?FileID=' + FileID + '&FileName=' + FileName, '_blank');