Compressing / Decompressing Folders & Files

Question

Does anyone know of a good way to compress or decompress files and folders in C# quickly? Handling large files might be necessary.

score 27 · Answer 1 · edited Mar 18 '20 at 11:24

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();
}

score 22 · Answer 2 · edited Dec 04 '12 at 20:29

22

I've always used the SharpZip Library.

Here's a link

edited Dec 04 '12 at 20:29

Konrad Viltersten

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answered Aug 01 '08 at 17:30

Tom Grochowicz

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Note: I found an *int overflow* bug in the SharpZip code years ago, that caused it to fail on random files that just happened to have the right combination of values. Not sure if that ever got fixed, but from memory I changed an `int` variable to a `long` in the SharpZip source to avoid the overflow. *I will have to try find my old fixed SharpZip code and check if it matches the latest*. – iCollect.it Ltd Mar 17 '14 at 16:41

score 10 · Answer 3 · edited Dec 24 '19 at 08:08

10

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.

edited Dec 24 '19 at 08:08

KoalaBear

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answered Aug 01 '08 at 17:28

alumb

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score 10 · Answer 4 · edited Apr 06 '19 at 14:03

10

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

edited Apr 06 '19 at 14:03

sashimi

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answered Aug 01 '08 at 18:04

Amit Joki · Answer 5 · 2014-12-15T09:02:35.023

8

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

edited Dec 15 '14 at 09:02

answered Nov 17 '13 at 16:08

Amit Joki

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score 6 · Answer 6 · edited Feb 23 '14 at 00:06

6

GZipStream is a really good utility to use.

edited Feb 23 '14 at 00:06

Zied R.

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answered May 13 '12 at 02:01

Darryl

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score 5 · Answer 7 · answered Aug 04 '08 at 23:52

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.

score 5 · Answer 8 · answered Dec 08 '11 at 22:29

5

Another good alternative is also DotNetZip.

answered Dec 08 '11 at 22:29

Rok

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score 0 · Answer 9 · edited Dec 24 '19 at 06:59

You can create zip file with this method:

public async Task<string> CreateZipFile(string sourceDirectoryPath, string name)
{
    var path = HostingEnvironment.MapPath(TempPath) + name;
    await Task.Run(() =>
    {
        if (File.Exists(path)) File.Delete(path);
        ZipFile.CreateFromDirectory(sourceDirectoryPath, path);
    });
    return path;
}

and then you can unzip zip file with this methods:

1- This method work with zip file path

public async Task ExtractZipFile(string filePath, string destinationDirectoryName)
{
    await Task.Run(() =>
    {
        var archive = ZipFile.Open(filePath, ZipArchiveMode.Read);
        foreach (var entry in archive.Entries)
        {
            entry.ExtractToFile(Path.Combine(destinationDirectoryName, entry.FullName), true);
        }
        archive.Dispose();
    });
}

2- This method work with zip file stream

public async Task ExtractZipFile(Stream zipFile, string destinationDirectoryName)
{
    string filePath = HostingEnvironment.MapPath(TempPath) + Utility.GetRandomNumber(1, int.MaxValue);
    using (FileStream output = new FileStream(filePath, FileMode.Create))
    {
        await zipFile.CopyToAsync(output);
    }
    await Task.Run(() => ZipFile.ExtractToDirectory(filePath, destinationDirectoryName));
    await Task.Run(() => File.Delete(filePath));
}

Compressing / Decompressing Folders & Files

9 Answers9