Question

How can I zip (In the server) multiple files to one archive?

Answer 1

Following code uses our Rebex ZIP and shows how to add files into the ZIP archive without using any temp file. The ZIP is then sent to the web browser.

// prepare MemoryStream to create ZIP archive within
using (MemoryStream ms = new MemoryStream())
{
    // create new ZIP archive within prepared MemoryStream
    using (ZipArchive zip = new ZipArchive(ms))
    {            
         // add some files to ZIP archive
         zip.Add(@"c:\temp\testfile.txt");
         zip.Add(@"c:\temp\innerfile.txt", @"\subfolder");

         // clear response stream and set the response header and content type
         Response.Clear();
         Response.ContentType = "application/zip";
         Response.AddHeader("content-disposition", "filename=sample.zip");

         // write content of the MemoryStream (created ZIP archive) 
         // to the response stream
         ms.WriteTo(Response.OutputStream);
    }
}

// close the current HTTP response and stop executing this page
HttpContext.Current.ApplicationInstance.CompleteRequest();

For more info see ZIP tutorial.

Alternative solution:

SharpZipLib and DotNetZip a widely used free alternatives.