static void Main(string[] args)
        {
            //1.获取从文件中读取的文本（假如文字如下）
            const string input = "测试文字：你好";

            //2.压缩
            var compressResult = GZip.Compress(input);

            //2.1 显示压缩结果
            Console.WriteLine(compressResult);

            //3.解压
            var decompressResult = GZip.Decompress(compressResult);

            //3.1 显示解压结果
            Console.WriteLine(decompressResult);

            Console.Read();
        }

public class GZip
    {
        /// <summary>
        ///     压缩
        /// </summary>
        /// <param name="text">文本</param>
        public static string Compress(string text)
        {
            var buffer = Encoding.UTF8.GetBytes(text);
            return Convert.ToBase64String(Compress(buffer));
        }

        /// <summary>
        ///     解压缩
        /// </summary>
        /// <param name="text">文本</param>
        public static string Decompress(string text)
        {
            var buffer = Convert.FromBase64String(text);
            using (var ms = new MemoryStream(buffer))
            {
                using (var zip = new GZipStream(ms, CompressionMode.Decompress))
                {
                    using (var reader = new StreamReader(zip))
                    {
                        return reader.ReadToEnd();
                    }
                }
            }
        }

        /// <summary>
        ///     压缩
        /// </summary>
        /// <param name="buffer">字节流</param>
        public static byte[] Compress(byte[] buffer)
        {
            if (buffer == null)
                return null;
            using (var ms = new MemoryStream())
            {
                using (var zip = new GZipStream(ms, CompressionMode.Compress, true))
                {
                    zip.Write(buffer, 0, buffer.Length);
                }

                return ms.ToArray();
            }
        }
    }