网站开发技巧, 使用byte[]持久化用户个性设置

场景, 网站用户的个性化配置较多, 而且容易发生增加和改变, 如何在数据库保存是个问题.

为了避免数据库表字段经常变更, 我们设计在表增加一个varbinary(max)字段存储个性化配置.

个性化的配置则存储到dictionary<string,string>中. 然后序列化成bytes即可.

见代码

先来一个帮助类

/// 

    /// 持久个性化设置的类
    /// 
    public  class ModelSetting
    {
        
        private Dictionary _hash;
        public ModelSetting() {
            _hash = new Dictionary();
        }

        /// 

        /// 把数据库中的bytes转化成可用的dictionary
        /// 
        /// 
        public void Load(byte[] bytes)
        {
            using (MemoryStream ms1 = new MemoryStream(bytes)) {
                BinaryFormatter bf = new BinaryFormatter();
                _hash = (Dictionary)bf.Deserialize(ms1);
            }
        }
        /// 

        /// 把实体中的dictionary转成bytes
        /// 
        /// 
        public byte[] ToByteArray()
        {
            using (MemoryStream ms1 = new MemoryStream())
            {
                BinaryFormatter b = new BinaryFormatter();
                b.Serialize(ms1, _hash);
                return ms1.ToArray();
            }
        }



        public ICollection Keys
        {
            get
            {
                return _hash.Keys;
            }
        }

        public string Get(string Name, string Def){
             if (_hash.ContainsKey(Name))
                 return _hash[Name];
             else
                 return Def;
        }
        public void Set(string Name, string Val)
        {
            if (Val == null)
                Val = "";
            _hash[Name] = Val;
        }
    }

然后在domain中的模型中增加如下代码

/// 

        /// Setting设置帮助类
        /// 
        protected ModelSetting modelsetting = new ModelSetting();
        private Dictionary _allSettings = new Dictionary();
        private bool _isLoaded = false;
        /// 

        /// 通过这个访问个性化设置
        /// 
        public Dictionary AllSettings
        {
            get {
                if (!_isLoaded)
                    LoadSettings();
                return _allSettings;
            }
        }

        /// 

        /// 将二进制的内容加载成具体的对象
        /// 
        private void LoadSettings()
        {
            if (Settings != null && Settings.Length > 1)
            {
                modelsetting.Load(Settings);

                _allSettings.Clear();
                foreach (string key in modelsetting.Keys)
                {
                    _allSettings.Add(key, modelsetting.Get(key, string.Empty));
                }

                _isLoaded = true;
            }
        }
        /// 

        /// 将单一的某个设置的键值对，存入网站本身二进制的Setting里.
        /// 本方法只是临时将键值对，放入字典。真正更新数据库，还需要SaveSetting()再Update（YibuSite）
        /// 
        /// 
        /// 
        public void SetOneSetting(string key, string value)
        {
            if (AllSettings.ContainsKey(key))
            {
                AllSettings[key] = value;
            }
            else
            {
                AllSettings.Add(key, value);
            }
        }
        public void SaveSetting()
        {
            foreach (string key in _allSettings.Keys)
            {
                modelsetting.Set(key, _allSettings[key]);
            }
            Settings = modelsetting.ToByteArray();
        }

存储和取值

public ActionResult TestModelSetting() {
            var temp = _userservice.Table.First();
            temp.SetOneSetting("xiaomi", "jianjialin");
            temp.SetOneSetting("mobile","13900000000");
            temp.SaveSetting();
            _userservice.Update(temp);

            var temp2 = _userservice.Table.First();
            return Content(temp2.AllSettings["xiaomi"]);
        }