[HttpGet]
[OutputCache(Duration = 60, VaryByParam = "none", Location =
OutputCacheLocation.Client, NoStore = true)]
public FileResult AppleUserDataReport()
{
    using (ZipFile zip = new ZipFile())
    {
        zip.Password = Membership.GeneratePassword(12, 1);
        var sb = _service.GetAppleUsersByClientId(User.ClientId);
        var reportName = "AppleUserData_Downloaded_" + DateTime.UtcNow.ToString("yyyy_MM_dd");

        var contentType = "text/xml";
        var bytes = Encoding.UTF32.GetBytes(sb.ToString());

        var result = new FileContentResult(bytes, contentType);
        result.FileDownloadName = reportName + ".csv";

        zip.AddFile(result.FileDownloadName, "file");
        zip.Save("C:\MyZipFile.zip");

        return result;
    }
}