.net byte string

public class Util
    {
        /// <summary>
        /// byte转换成string
        /// </summary>
        /// <param name="bts"></param>
        /// <returns></returns>
        public static string ByteToString(byte[] bts)
        {
            if(bts==null||bts.Length<=0)
            {
                return null;
            }
            Encoding cod=Encoding.UTF8;
            return cod.GetString(bts);
        }

        /// <summary>
        /// string转换成byte
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static byte[] StringToByte(string str)
        {
            if(string.IsNullOrEmpty(str))
            {
                return null;
            }
            Encoding cod = Encoding.UTF8;
            return cod.GetBytes(str);
        }

        /// <summary>
        /// byte转换成stream
        /// </summary>
        /// <param name="bts"></param>
        /// <returns></returns>
        public static Stream ByteToStream(byte[] bts)
        {
            return new MemoryStream(bts);
        }

        /// <summary>
        /// stream转换成byte
        /// </summary>
        /// <param name="stream"></param>
        /// <returns></returns>
        public static byte[] StreamToByte(Stream stream)
        {
            MemoryStream ms = new MemoryStream();
            var buff = new byte[0x100];
            for(var i= stream.Read(buff,0,buff.Length);i>0;i= stream.Read(buff,0,buff.Length))
            {
                ms.Write(buff, 0, i);
            }
            stream.Close();
            return ms.ToArray();
        }

        /// <summary>
        /// stream转换成byte
        /// </summary>
        /// <param name="stream"></param>
        /// <returns></returns>
        public static byte[] StreamToByte1(Stream stream)
        {
            byte[] bt = new byte[stream.Length];
            stream.Read(bt, 0, bt.Length);
            stream.Seek(0, SeekOrigin.Begin);
            return bt;
        }

        /// <summary>
        /// stream转换成文件
        /// </summary>
        /// <param name="stream"></param>
        /// <param name="fileName"></param>
        public static void StreamToFile(Stream stream,string fileName)
        {
            FileStream file = new FileStream(fileName, FileMode.Create);
            byte[] bt = new byte[stream.Length];
            stream.Read(bt, 0, bt.Length);
            stream.Seek(0, SeekOrigin.Begin);
            BinaryWriter bw = new BinaryWriter(file);
            bw.Write(bt);
            bw.Close();
            file.Close();
        }

        /// <summary>
        /// file转换成stream
        /// </summary>
        /// <param name="fileName"></param>
        /// <returns></returns>
        public static Stream FileToStream(string fileName)
        {
            FileStream file = new FileStream(fileName, FileMode.Open);
            byte[] bt = new byte[file.Length];
            file.Read(bt, 0, bt.Length);
            file.Close();
            Stream stream = new MemoryStream(bt);
            return stream;
        }

        /// <summary>
        /// 获取文件的哈希散列值
        /// </summary>
        /// <param name="bts"></param>
        /// <returns></returns>
        public static string MD5Hash(byte[] bts)
        {
            var md5Csp = new System.Security.Cryptography.MD5CryptoServiceProvider();
            byte[] md5Out= md5Csp.ComputeHash(bts);
            return BitConverter.ToString(md5Out).Replace("-", "").ToLower();
        }

        /// <summary>
        /// 获取字符串的哈希散列值
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string StringToMDHash(string str)
        {
            if(string.IsNullOrEmpty(str))
            {
                return null;
            }
            var md5Csp = new System.Security.Cryptography.MD5CryptoServiceProvider();
            byte[] md5Out = md5Csp.ComputeHash(Encoding.UTF8.GetBytes(str));
            return BitConverter.ToString(md5Out).Replace("-", "").ToLower();
        }

        /// <summary>
        /// byte压缩
        /// </summary>
        /// <param name="compress"></param>
        /// <returns></returns>
        public static byte[] Compress(byte[] uncompress)
        {
            MemoryStream ms = new MemoryStream();
            using (GZipStream gzs = new GZipStream(ms, CompressionMode.Compress))
            {
                gzs.Write(uncompress, 0, uncompress.Length);
                gzs.Close();
                return ms.ToArray();
            }
        }

        /// <summary>
        /// byte解压
        /// </summary>
        /// <param name="compress"></param>
        /// <returns></returns>
        public static byte[] Decompress(Stream stream)
        {
            var buff = new byte[4096];
            GZipStream gzs = new GZipStream(stream, CompressionMode.Decompress);
            using (MemoryStream ms = new MemoryStream())
            {
                for(var r=-1;r!=0;r=gzs.Read(buff,0,buff.Length))
                {
                    if(r>0)
                    {
                        ms.Write(buff, 0, r);
                    }
                }
                return ms.ToArray();
            }
        }

    }

　　这篇文章主要是string和byte数组之间的转换，stream和byte之间的转换，byte，stream的解压与压缩，还有文件和stream之间的转变