C#中string与byte[]的转换帮助类

using System;
using System.Text;
namespace SidleHelper
{
     /// <summary>
     /// Summary description for StrHelper.
     /// 命名缩写：
     /// Str: unicode string
     /// Arr: unicode array
     /// Hex: 二进制数据
     /// Hexbin: 二进制数据用ASCII字符表示 例 字符"1"的hex是0x31表示为hexbin是 "3""1" 
     /// Asc: ASCII
     /// Uni: UNICODE
     /// </summary>
     public sealed class StrHelper
     {
          #region Hex与Hexbin的转换
          public static void Hexbin2Hex(byte[] bHexbin, byte[] bHex, int nLen)
          {
                for (int i = 0; i < nLen / 2; i++)
                {
                     if (bHexbin[2 * i] < 0x41)
                     {
                          bHex[i] = Convert.ToByte(((bHexbin[2 * i] - 0x30) << 4) & 0xf0);
                     }
                     else
                     {
                          bHex[i] = Convert.ToByte(((bHexbin[2 * i] - 0x37) << 4) & 0xf0);
                     }
                     if (bHexbin[2 * i + 1] < 0x41)
                     {
                          bHex[i] |= Convert.ToByte((bHexbin[2 * i + 1] - 0x30) & 0x0f);
                     }
                     else
                     {
                          bHex[i] |= Convert.ToByte((bHexbin[2 * i + 1] - 0x37) & 0x0f);
                     }
                }
          }
          public static byte[] Hexbin2Hex(byte[] bHexbin, int nLen)
          {
                if (nLen % 2 != 0)
                     return null;
                byte[] bHex = new byte[nLen / 2];
                Hexbin2Hex(bHexbin, bHex, nLen);
                return bHex;
          }
          public static void Hex2Hexbin(byte[] bHex, byte[] bHexbin, int nLen)
          {
                byte c;
                for (int i = 0; i < nLen; i++)
                {
                     c = Convert.ToByte((bHex[i] >> 4) & 0x0f);
                     if (c < 0x0a)
                     {
                          bHexbin[2 * i] = Convert.ToByte(c + 0x30);
                     }
                     else
                     {
                          bHexbin[2 * i] = Convert.ToByte(c + 0x37);
                     }
                     c = Convert.ToByte(bHex[i] & 0x0f);
                     if (c < 0x0a)
                     {
                          bHexbin[2 * i + 1] = Convert.ToByte(c + 0x30);
                     }
                     else
                     {
                          bHexbin[2 * i + 1] = Convert.ToByte(c + 0x37);
                     }
                }
          }
          public static byte[] Hex2Hexbin(byte[] bHex, int nLen)
          {
                byte[] bHexbin = new byte[nLen * 2];
                Hex2Hexbin(bHex, bHexbin, nLen);
                return bHexbin;
          }
          #endregion
          #region 数组和字符串之间的转化
          public static byte[] Str2Arr(String s)
          {
                return (new UnicodeEncoding()).GetBytes(s);
          }
          public static string Arr2Str(byte[] buffer)
          {
                return (new UnicodeEncoding()).GetString(buffer, 0, buffer.Length);
          }
          public static byte[] Str2AscArr(String s)
          {
                return System.Text.UnicodeEncoding.Convert(System.Text.Encoding.Unicode,
                System.Text.Encoding.ASCII,
                Str2Arr(s));
          }
          public static byte[] Str2HexAscArr(String s)
          {
                byte[] hex = Str2AscArr(s);
                byte[] hexbin = Hex2Hexbin(hex, hex.Length);
                return hexbin;
          }
          public static string AscArr2Str(byte[] b)
          {
                return System.Text.UnicodeEncoding.Unicode.GetString(
                System.Text.ASCIIEncoding.Convert(System.Text.Encoding.ASCII,
                System.Text.Encoding.Unicode,
                b)
                );
          }
          public static string HexAscArr2Str(byte[] buffer)
          {
                byte[] b = Hex2Hexbin(buffer, buffer.Length);
                return AscArr2Str(b);
          }
          #endregion
     }
}