Compressing / Decompressing Folders & Files

Question

The .Net 2.0 framework namespace System.IO.Compression supports GZip and Deflate algorithms. Here are two methods that compress and decompress a byte stream which you can get from your file object. You can substitute GZipStream for DefaultStream in the methods below to use that algorithm. This still leaves the problem of handling files compressed with different algorithms though.

public static byte[] Compress(byte[] data)
{
    MemoryStream output = new MemoryStream();

    GZipStream gzip = new GZipStream(output, CompressionMode.Compress, true);
    gzip.Write(data, 0, data.Length);
    gzip.Close();

    return output.ToArray();
}

public static byte[] Decompress(byte[] data)
{
    MemoryStream input = new MemoryStream();
    input.Write(data, 0, data.Length);
    input.Position = 0;

    GZipStream gzip = new GZipStream(input, CompressionMode.Decompress, true);

    MemoryStream output = new MemoryStream();

    byte[] buff = new byte[64];
    int read = -1;

    read = gzip.Read(buff, 0, buff.Length);

    while (read > 0)
    {
        output.Write(buff, 0, read);
        read = gzip.Read(buff, 0, buff.Length);
    }

    gzip.Close();

    return output.ToArray();
}

I've always used the SharpZip Library.

Here's a link

You can use a 3rd-party library such as SharpZip as Tom pointed out.

Another way (without going 3rd-party) is to use the Windows Shell API. You'll need to set a reference to the Microsoft Shell Controls and Automation COM library in your C# project. Gerald Gibson has an example at:

Internet Archive's copy of the dead page

As of .Net 1.1 the only available method is reaching into the java libraries.

Using the Zip Classes in the J# Class Libraries to Compress Files and Data with C#

Not sure if this has changed in recent versions.

My answer would be close your eyes and opt for DotNetZip. It's been tested by a large community.

GZipStream is a really good utility to use.

This is very easy to do in java, and as stated above you can reach into the java.util.zip libraries from C#. For references see:

java.util.zip javadocs
sample code

I used this a while ago to do a deep (recursive) zip of a folder structure, but I don't think I ever used the unzipping. If I'm so motivated I may pull that code out and edit it into here later.