ASP.NET MVC - how to zip and download files from database?

Question

I'm new to ASP.NET MVC and I'm trying to figure out how to zip and download files stored in a database.

Do I need to zip the files, save them in memory or server, and then send that file to the user. I would rather not save it on the server.

Model:

    public class Document
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string ContentType { get; set; }
        public byte[] Content { get; set; }
    }

Controller:

    [HttpPost]
    [Route("~/document/zip/{token}")]
    public ActionResult DownloadZip(string token)
    {
        // EF6
        var docs = db.Documents.ToList();

        using (var memoryStream = new MemoryStream())
        {
            using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
            {
                foreach (var doc in docs)
                {
                    var file = archive.CreateEntry(doc.Name.ToString());
                    using (var streamWriter = new StreamWriter(file.Open()))
                    {
                        streamWriter.Write(doc.Name.ToString());
                    }
                }
            }

            return File(memoryStream.ToArray(), "~/WebApplication/Documents", "xxxx.zip");
        };
    }

Answer 1

If you want put your content to file, you have to take stream from file.Open() and write byte array to this stream

[HttpPost]
[Route("~/document/zip/{token}")]
public ActionResult DownloadZip(string token)
{
    // EF6
    var docs = db.Documents.ToList();

    using (var memoryStream = new MemoryStream())
    {
        using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
        {
            foreach (var doc in docs)
            {
                var file = archive.CreateEntry(doc.Name.ToString());
                using (var stream = file.Open())
                {
                    stream.Write(doc.Content, 0, doc.Content.Length);
                }
            }
        }

        return File(memoryStream.ToArray(), "application/zip", "xxxx.zip");
    };
}