Create zip file in memory from bytes (text with arbitrary encoding)

Question

The application i\'m developing needs to compress xml files into zip files and send them through http requests to a web service. As I dont need to keep the zip files, i\'m j

Answer 1

You are trying to get bytes from MemoryStream too early, ZipArchive did not write them all yet. Instead, do like this:

using (var memoryStream = new MemoryStream()) {
    // note "leaveOpen" true, to not dispose memoryStream too early
    using (var zipArchive = new ZipArchive(memoryStream, ZipArchiveMode.Create, leaveOpen: true)) {
        var zipEntry = zipArchive.CreateEntry(fileName);
        using (Stream entryStream = zipEntry.Open()) {
            entryStream.Write(bytes, 0, bytes.Length);
        }                    
    }
    // now, after zipArchive is disposed - all is written to memory stream
    zipBytes = memoryStream.ToArray();
}

Answer 2

If you use a memory stream to load your text you can control the encoding type and it works across a WCF service. This is the implementation i am using currently and it works on my WCF services

    private byte[] Zip(string text)
    {
        var bytes = Encoding.UTF8.GetBytes(text);

        using (var msi = new MemoryStream(bytes))
        using (var mso = new MemoryStream())
        {
            using (var gs = new GZipStream(mso, CompressionMode.Compress))
            {
                CopyTo(msi, gs);
            }

            return mso.ToArray();
        }
    }

    private string Unzip(byte[] bytes)
    {
        using (var msi = new MemoryStream(bytes))
        using (var mso = new MemoryStream())
        {
            using (var gs = new GZipStream(msi, CompressionMode.Decompress))
            {
                CopyTo(gs, mso);
            }

            return Encoding.UTF8.GetString(mso.ToArray());
        }
    }