C#对GZIP压缩和解压

/// <summary>
/// 将Gzip的byte数组读取为字符串
/// </summary>
/// <param name="bytes"></param>
/// <param name="encoding"></param>
/// <returns></returns>
public static string ReadGzip(byte[] bytes, string encoding = "GB2312")
{
    string result = string.Empty;
    using (MemoryStream ms = new MemoryStream(bytes))
    {
        using (GZipStream decompressedStream = new GZipStream(ms, CompressionMode.Decompress))
        {
            using (StreamReader sr = new StreamReader(decompressedStream, Encoding.GetEncoding(encoding)))
            {
                result = sr.ReadToEnd();
            }
        }
    }
    return result;
}

/// <summary>
/// 将字符串压缩成Gzip格式的byte数组
/// </summary>
/// <param name="str"></param>
/// <param name="encoding"></param>
/// <returns></returns>
public static byte[] WriteGzip(string str, string encoding = "GB2312")
{
    byte[] rawData = System.Text.Encoding.UTF8.GetBytes(str);
    using (MemoryStream ms = new MemoryStream())
    {
        GZipStream compressedzipStream = new GZipStream(ms, CompressionMode.Compress, true);
        compressedzipStream.Write(rawData, 0, rawData.Length);
        compressedzipStream.Close();
        return ms.ToArray();
    }
}

/// <summary>
/// 解压Gzip文件，返回字符串
/// </summary>
/// <param name="fileName">文件全路径</param>
/// <returns>字符串</returns>
public static string ReadGzipFromFile(string fileName)
{
    using (FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read))
    {
        using (GZipStream decompressedStream = new GZipStream(fileStream, CompressionMode.Decompress))
        {
            StreamReader reader = new StreamReader(decompressedStream);
            string result = reader.ReadToEnd();//重点
            reader.Close();
            return result;
        }
    }
}

外面可以通过File.ReadAllBytes()和File.WriteAllBytes()进行文件的操作。而GZIP文件的后缀名为.gz

灵感来源：http://www.cnblogs.com/gengaixue/p/3300664.html