C#: json字串中的特殊字元處理

#region 實現js eval功能, 如:200+200+200-200+210 * 210        public static decimal EvalExpression(string strExpression)        {            Microsoft.JScript.Vsa.VsaEngine engine = Microsoft.JScript.Vsa.VsaEngine.CreateEngine();            if (string.IsNullOrEmpty(strExpression))                return 0 ;            else                        return Convert.ToDecimal(Microsoft.JScript.Eval.JScriptEvaluate(strExpression, engine));                   }        #endregion

#region 將一個資料錶轉換成一個JSON字串，在用戶端可以直接轉換成二維數組。        /// <summary>        /// 將一個資料錶轉換成一個JSON字串，在用戶端可以直接轉換成二維數組。        /// </summary>        /// <param name="source">需要轉換的表。</param>        /// <returns></returns>        public static string DataTableToJson(DataTable source)        {            if (source.Rows.Count == 0)                return "";            StringBuilder sb = new StringBuilder("[");            foreach (DataRow row in source.Rows)            {                sb.Append("[");                for (int i = 0; i < source.Columns.Count; i++)                {                    sb.Append('"' + row[i].ToString().Replace("\\", "\\\\").Replace("\'", "\\\'").Replace("\t", " ").Replace("\r", " ").Replace("\n", "<br/>").Replace("\"", "'") + "\",");                }                sb.Remove(sb.Length - 1, 1);                sb.Append("],");            }            sb.Remove(sb.Length - 1, 1);            sb.Append("]");            return sb.ToString();        }                        /// <summary>        /// 返回JSON資料到前台        /// </summary>        /// <param name="dt">資料表</param>        /// <returns>JSON字串</returns>        public static string DataTableToJsonParam(DataTable dt)        {            StringBuilder JsonString = new StringBuilder();                             if (dt != null && dt.Rows.Count > 0)            {                JsonString.Append("[ ");                               for (int i = 0; i < dt.Rows.Count; i++)                {                    JsonString.Append("{ ");                    for (int j = 0; j < dt.Columns.Count; j++)                    {                        if (j < dt.Columns.Count - 1)                        {                            JsonString.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + "\"" + dt.Rows[i][j].ToString().Replace("\\", "\\\\").Replace("\'", "\\\'").Replace("\t", " ").Replace("\r", " ").Replace("\n", "<br/>").Replace("\"", "'") + "\",");                        }                        else if (j == dt.Columns.Count - 1)                        {                            JsonString.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + "\"" + dt.Rows[i][j].ToString().Replace("\\", "\\\\").Replace("\'", "\\\'").Replace("\t", " ").Replace("\r", " ").Replace("\n", "<br/>").Replace("\"", "'") + "\"");                        }                    }                    /**/                    /*end Of String*/                    if (i == dt.Rows.Count - 1)                    {                        JsonString.Append("} ");                    }                    else                    {                        JsonString.Append("}, ");                    }                }                JsonString.Append("]");                return JsonString.ToString();            }            else            {                return ""; ;            }        }        #endregion