Compressing and decompressing folder and files using GZipStream in C#

In this article, learn how to compressing and decompressing folder and files using GZipStream in C#.

How to compressing and decompressing folder and files in C#:

The namespace System.IO.Compression supports GZip and Deflate algorithms. There 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.

1. How to Compress files and folders using GZipStream:

.
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();
}
.

2. How to Decompress files and folders using GZipStream:

.
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();
}
.

Here is an another example of how to use the FileSystem class to compress a file:

using System.IO;
using System.IO.Compression;

class Program
{
    static void Main(string[] args)
    {
        string fileToCompress = @"C:\example.txt";
        string compressedFile = @"C:\example.txt.gz";

        using (FileStream originalFileStream = File.OpenRead(fileToCompress))
        {
            using (FileStream compressedFileStream = File.Create(compressedFile))
            {
                using (GZipStream compressionStream = new GZipStream(compressedFileStream, CompressionMode.Compress))
                {
                    originalFileStream.CopyTo(compressionStream);
                }
            }
        }
    }
}

In this example, we are using the File.OpenRead method to open the file we want to compress, the File.Create method to create a new file stream for the compressed file and GZipStream to compress the original file stream.

Here is an example of how to use the FileSystem class to decompress a file:

using System.IO;
using System.IO.Compression;

class Program
{
    static void Main(string[] args)
    {
        string compressedFile = @"C:\example.txt.gz";
        string decompressedFile = @"C:\example.txt";

        using (FileStream compressedFileStream = File.OpenRead(compressedFile))
        {
            using (FileStream decompressedFileStream = File.Create(decompressedFile))
            {
                using (GZipStream decompressionStream = new GZipStream(compressedFileStream, CompressionMode.Decompress))
                {
                    decompressionStream.CopyTo(decompressedFileStream);
                }
            }
        }

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