asp.net对象合并

public class com
    {
        /// <summary>
        /// 把参数转为JSON字符串
        /// </summary>
        /// <param name="all">所有的参娄</param>
        /// <returns>JSON字符串</returns>
        public static Hashtable StringToJSON(string all)
        {
            Hashtable ht = new Hashtable();
            string[] arpar = all.Split('&');
            foreach (string p in arpar)
                ht.Add(p.Split('=')[0], p.Split('=')[1]);
            return ht;
        }
        /// <summary>
        /// 对象合并之后的JSON字符串
        /// </summary>
        /// <param name="str">参数对象</param>
        /// <param name="obj">原始对象</param>
        /// <returns>合并后的字符串</returns>
        public static string extend(object obj, Hashtable hashTable)
        {
            Hashtable ht = new Hashtable();
            List<string> listobj = new List<string>();
            foreach (PropertyInfo pi in obj.GetType().GetProperties())
                listobj.Add(pi.Name);
            
            List<string> listpar = new List<string>();
            foreach (DictionaryEntry de in hashTable)
                listpar.Add(de.Key.ToString());

            //当存在的时候添加新值
            foreach (DictionaryEntry de in hashTable)
                if (listobj.Contains(de.Key.ToString()))
                    ht.Add(de.Key.ToString(), de.Value.ToString());
            //当不存在的时候添加默认值
            foreach (PropertyInfo pi in obj.GetType().GetProperties())
                if (!listpar.Contains(pi.Name))
                    ht.Add(pi.Name, pi.GetValue(obj, null));
            JavaScriptSerializer serializer = new JavaScriptSerializer();
            return new JavaScriptSerializer().Serialize(ht);             
        }
    }

 foreach( string key in allkeys )