压缩解压缩字符串

/// <summary>
        /// 压缩字符串
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string Compress(string str)
        {
            if (string.IsNullOrEmpty(str))
            {
                return "";
            }
            byte[] bytes = Encoding.UTF8.GetBytes(str);
            using (MemoryStream ms = new MemoryStream(1024))
            {
                StringBuilder sb = new StringBuilder();
                using (GZipStream compress = new GZipStream(ms, System.IO.Compression.CompressionMode.Compress))
                {
                    compress.Write(bytes, 0, bytes.Length);
                }
                byte[] byteArray = ms.ToArray();
                foreach (byte b in byteArray)
                {
                    sb.Append((char)b);
                }
                return sb.ToString();
            }
        }

        /// <summary>
        /// 解压字符串
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string Decompress(string str)
        {
            if (string.IsNullOrEmpty(str))
            {
                return "";
            }
            List<byte> bytes = new List<byte>(str.Length);
            foreach (char c in str)
            {
                bytes.Add((byte)c);
            }
            using (MemoryStream ms = new MemoryStream(bytes.ToArray()))
            {
                using (GZipStream decompress = new GZipStream(ms, System.IO.Compression.CompressionMode.Decompress))
                {
                    using (StreamReader reader = new StreamReader(decompress))
                    {
                        return reader.ReadToEnd();
                    }
                }
            }
        }