A Programmer with Microsoft tools

Sometimes you need to send to the user more than 1 file – or, maybe, the file is too large
The simplest way is : made a zip file that contains the others.

What do you need
1. SharpzipLib from http://www.icsharpcode.net/opensource/sharpziplib/ ( or download via NuGet in VS)
2. obtain the file(s) that you want as a string or as a byte[] – let’s say you have a byte[] to store in a str variable
3. make in your action something like that:

 var fcr = new ZipResult("Export.xls", str);
            fcr.AddFile("readme.txt","this zip file contains ..");
            return fcr;

4. copy the following code in your asp.net mvc projects:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.IO;
using ICSharpCode.SharpZipLib.Zip;
using System.Text;

namespace utilsResult
{
    public class ZipResult : FileResult
    {

        
        private Dictionary<string, byte[]> content = new Dictionary<string, byte[]>();
        public string FileNameZip;
        public ZipResult(string FileName, byte[] Contents)
            : base("application/octet-stream")
        {
            this.FileDownloadName = Path.GetFileNameWithoutExtension(FileName) + ".zip";
            AddFile(FileName, Contents);
        }
        public void AddFile(string FileName,  byte[] Contents)
        {
            content.Add(FileName, Contents);
        }
        public void AddFile(string FileName,string Contents, Encoding e = null)
        {
            if (e == null)
                e = ASCIIEncoding.ASCII;

            content.Add(FileName, e.GetBytes(Contents));
        }

        protected override void WriteFile(HttpResponseBase response)
        {

            using (ZipOutputStream zos = new ZipOutputStream(response.OutputStream))
            {
                zos.SetLevel(3);
                zos.UseZip64=UseZip64.Off;

                foreach (var item in content)
                {
                    ZipEntry ze = new ZipEntry(item.Key);
                    ze.DateTime = DateTime.Now;                    
                    zos.PutNextEntry(ze);
                    int count=item.Value.Length;
                    zos.Write(item.Value, 0, count);
                   
                    
                }                
            }
        }
    }
}

5. future improvements:
Zip the file(s) in a dll project to made fully testable!