在不使用C# Encoding类情况下编码转换

        /// <summary>
        /// 中文转unicode
         /// </summary>
         /// <returns></returns>
         public static string unicode_0(string str)
         {
             string outStr = "";
             if (!string.IsNullOrEmpty(str))
             {
                 for (int i = 0; i < str.Length; i++)
                 {
                     outStr += "/u" + ((int)str[i]).ToString("x");
                 }
             }
             return outStr;
         }
         /// <summary>
         /// unicode转中文
        /// </summary>
         /// <returns></returns>
         public static string unicode_1(string str)
         {
             string outStr = "";  
             if (!string.IsNullOrEmpty(str))  
             {  
                 string[] strlist = str.Replace("/","").Split('u');  
                 try  
                 {  
                     for (int i = 1; i < strlist.Length; i++)  
                     {  
                         //将unicode字符转为10进制整数，然后转为char中文字符  
                         outStr += (char)int.Parse(strlist[i], System.Globalization.NumberStyles.HexNumber);  
                     }  
                 }  
                 catch (FormatException ex)  
                 {  
                     outStr = ex.Message;  
                 }  
             }
             return outStr;

        }




        /// <summary>
         /// unicode转中文（符合js规则的）
        /// </summary>
         /// <returns></returns>
         public static string unicode_js_1(string str)
         {
             string outStr = "";
             Regex reg = new Regex(@"(?i)\\u([0-9a-f]{4})");
             outStr = reg.Replace(str, delegate(Match m1)
             {
                 return ((char)Convert.ToInt32(m1.Groups[1].Value, 16)).ToString();
             });
             return outStr;
         }
         /// <summary>
         /// 中文转unicode（符合js规则的）
        /// </summary>
         /// <returns></returns>
         public static string unicode_js_0(string str)
         {
             string outStr = "";
             string a = "";
             if (!string.IsNullOrEmpty(str))
             {
                 for (int i = 0; i < str.Length; i++)
                 {
                     if (Regex.IsMatch(str[i].ToString(), @"[\u4e00-\u9fa5]")) { outStr += "\\u" + ((int)str[i]).ToString("x"); }
                     else { outStr += str[i]; }
                 }
             }
             return outStr;
         }