X++ generate zip file.

    System.IO.MemoryStream zipFileContents     = new System.IO.MemoryStream();
    // zip the file
    using (System.IO.Compression.ZipArchive zipArchive = new System.IO.Compression.ZipArchive(zipFileContents, System.IO.Compression.ZipArchiveMode::Create, true))
    {
        foreach( item in list)
        {
            System.IO.Compression.ZipArchiveEntry fileEntry = zipArchive.CreateEntry( foundryWipCategory.Device +' '+ fileSuf  );
            
            System.IO.MemoryStream fileStream = item;
            //原文中这里是使用streamReader.ReadToEnd() String中转，可能造成编码问题，除非是纯文本文件，慎用。
            using(var s = fileEntry.Open() )
            {
                fileStream.CopyTo(s);
            }
        }
    }
    zipFileContents.Position = 0;
    //file::SendFileToUser( this.genFile('8176AL1D'), FileSuf);
    file::SendFileToUser(zipFileContents, zipSuf);

refer from