C#把UNICODE编码转换为GB编码的实例

public string unicodetogb(string text)
    {
      System.Text.RegularExpressions.MatchCollection mc = System.Text.RegularExpressions.Regex.Matches(text,"\u([w]{4})");
      if (mc != null && mc.Count > 0)
      {
        foreach (System.Text.RegularExpressions.Match m2 in mc)
        {
          string v = m2.Value;
          string word = v.Substring(2);
          byte[] codes = new byte[2];
          int code = Convert.ToInt32(word.Substring(0,2),16);
          int code2 = Convert.ToInt32(word.Substring(2),16);
          codes[0] = (byte)code2;
          codes[1] = (byte)code;
          text = text.Replace(v,Encoding.Unicode.GetString(codes));
        }
      }
      else
      {

      }
      return text;
    }