基於中繼資料驅動模型架構在ASP.Net的應用研究

目前流行的asp.net架構很多，有開源的有模式與實踐(Microsoft patterns & practices)小組的開源項目Web Service

Factory,Nhibernet, Nbear　ORM, Petshop等架構； 下面我又介紹另一種基於中繼資料(XML)架構，在ASP.net2.0的程

序應用，而且這種架構目前很多 IT公司使 用較少，它的特點靈活度較高， 簡單高效，方便的IOC依賴注入，對象 間

解偶性好，開發效率較高，可以結合微軟企業庫進行 高效率的儲存。 我在微軟互聯星空項目中，微軟有很好的成功案例。

 

總體思想是採用XML（Template模板）進行許可權控制，參考：

首先在Global.asax設定全域對象，系統啟動後會把相關持久對象裝入記憶體，提高系統運行速度：

相關代碼如下：

<%@ Application Language="C#" %>
<%@ Import Namespace="Microsoft.XXXXX.Advertising.SystemFrameWork" %>

<script runat="server">

    void Application_Start(object sender, EventArgs e)
    {
        SystemVM VM = new SystemVM();
        Application.Lock();
        Application["VM"] = VM;
        Application.UnLock();
       
    }
   
    void Application_End(object sender, EventArgs e)
    {
        //  在應用程式關閉時啟動並執行代碼

    }
       
    void Application_Error(object sender, EventArgs e)
    {
        // 在出現未處理的錯誤時啟動並執行代碼

    }

    void Session_Start(object sender, EventArgs e)
    {
        // 在新會話啟動時啟動並執行代碼

    }

    void Session_End(object sender, EventArgs e)
    {
        // 在會話結束時啟動並執行代碼。
        // 注意: 只有在 Web.config 檔案中的 sessionstate 模式設定為
        // InProc 時，才會引發 Session_End 事件。如果會話模式設定為 StateServer
        // 或 SQLServer，則不會引發該事件。

    }
      
</script>  

第二，建立SystemVM.cs驅動模型類，包括一些相關屬性和裝載相關Template模板：

 

部分邏輯流程如下：

簡略代碼如下： 
    public class SystemVM
    {
        //角色模板
        private SystemService m_system = null;
        private OrderService m_order = null;
        private QueryService m_query = null;
        private FoundationService m_found = null;

        /// <summary>
        ///
        /// </summary>
        public XmlNode XmlDimension
        {
            get
            {
                if (HttpContext.Current.Cache["dimension"] == null)
                {
                    LoadXmlDimension();
                }
                return (XmlNode)HttpContext.Current.Cache["dimension"];
            }
        }
        /// <summary>
        /// 查詢範本
        /// </summary>
        public XmlNode XmlQueryList
        {
            get
            {
                if (HttpContext.Current.Cache["querylist"] == null)
                {
                    LoadXmlQueryList();
                }
                return (XmlNode)HttpContext.Current.Cache["querylist"];
            }
        }

        /// <summary>
        /// JavaScript模板
        /// </summary>
        public XmlNode XmlJavaScript
        {
            get
            {
                if (HttpContext.Current.Cache["javascript"] == null)
                {
                    LoadXmlJavaScript();
                }
                return (XmlNode)HttpContext.Current.Cache["javascript"];
            }
        }
        /// <summary>
        /// 省分模板
        /// </summary>
        public XmlNode XmlProvince
        {
            get
            {
                if (HttpContext.Current.Cache["province"] == null)
                {
                    LoadXmlProvince();
                }
                return (XmlNode)HttpContext.Current.Cache["province"];
            }
        }
        #region 多角色模板
        /// <summary>
        /// 系統角色模板
        /// </summary>
        public XmlNode XmlTemplate
        {
            get
            {
                XmlNode xmlNode = null;
                if (HttpContext.Current.Request.Cookies["user"] != null)
                {
                    string sWebSiteType = HttpContext.Current.Request.Cookies["user"]["WebSiteType"];

                    if (sWebSiteType == "0")
                    {
                        xmlNode = XmlCenterTemplate;
                    }
                    if (sWebSiteType == "1")
                    {
                        xmlNode = XmlProvinceTemplate;
                    }
                    if (sWebSiteType == "2")
                    {
                        xmlNode = XmlCityTemplate;
                    }

                }
                return xmlNode;
            }
        }

        public XmlNode XmlCenterTemplate
        {
            get
            {
                if (HttpContext.Current.Cache["CenterTemplate"] == null)
                {
                    LoadXmlCenterTemplate();
                }
                return (XmlNode)HttpContext.Current.Cache["CenterTemplate"];
            }
        }
        public XmlNode XmlProvinceTemplate
        {
            get
            {
                if (HttpContext.Current.Cache["ProvinceTemplate"] == null)
                {
                    LoadXmlProvinceTemplate();
                }
                return (XmlNode)HttpContext.Current.Cache["ProvinceTemplate"];
            }
        }
        public XmlNode XmlCityTemplate
        {
            get
            {
                if (HttpContext.Current.Cache["CityTemplate"] == null)
                {
                    LoadXmlCityTemplate();
                }
                return (XmlNode)HttpContext.Current.Cache["CityTemplate"];
            }
        }
        /// <summary>
        /// 加栽角色權限範本
        /// </summary>
        private void LoadXmlCenterTemplate()
        {
            string strBasePath = AppDomain.CurrentDomain.BaseDirectory;
            XmlDocument doc = new XmlDocument();
            string sPath = strBasePath + @"Template\" + "CenterTemplate.Config";
            doc.Load(sPath);
            XmlNode xmlNode = doc.DocumentElement;
            HttpContext.Current.Cache.Insert("CenterTemplate", doc.DocumentElement,
              new CacheDependency(sPath));
        }
        private void LoadXmlProvinceTemplate()
        {
            string strBasePath = AppDomain.CurrentDomain.BaseDirectory;
            XmlDocument doc = new XmlDocument();
            string sPath = strBasePath + @"Template\" + "ProvinceTemplate.Config";
            doc.Load(sPath);
            XmlNode xmlNode = doc.DocumentElement;
            HttpContext.Current.Cache.Insert("ProvinceTemplate", doc.DocumentElement,
              new CacheDependency(sPath));
        }
        private void LoadXmlCityTemplate()
        {
            string strBasePath = AppDomain.CurrentDomain.BaseDirectory;
            XmlDocument doc = new XmlDocument();
            string sPath = strBasePath + @"Template\" + "CityCenterTemplate.Config";
            doc.Load(sPath);
            XmlNode xmlNode = doc.DocumentElement;
            HttpContext.Current.Cache.Insert("CityTemplate", doc.DocumentElement,
              new CacheDependency(sPath));
        }
        #endregion
        /// <summary>
        /// 系統服務
        /// </summary>
        public SystemService SystemService
        {
            get
            {
                return m_system;
            }
        }
        /// <summary>
        /// 查詢服務
        /// </summary>
        public QueryService QueryService
        {
            get
            {
                return m_query;
            }
        }
        /// <summary>
        /// 基礎資訊
        /// </summary>
        public FoundationService FoundationService
        {
            get
            {
                return m_found;
            }
        }
        /// <summary>
        /// 訂單管理
        /// </summary>
        public OrderService OrderService
        {
            get
            {
                return m_order;
            }
        }
        public SystemVM()
        {
            LoadBusinessObj();
        }
        /// <summary>
        /// 根據模板類型，返回系統可以選擇的模板種類。
        /// </summary>
        /// <param name="sType"></param>
        /// <returns></returns>
        public XmlNodeList GetXmlJavaScriptByType(string sType)
        {
            XmlNodeList xmlNodeList = XmlJavaScript.SelectNodes("//項[@類型='" + sType + "']");
            if (xmlNodeList.Count<0)
            {
                throw new Exception("找不到類型為["+sType+"]的節點！");
            }
            return xmlNodeList;
        }
        /// <summary>
        /// 根據模板名稱，擷取JavaScript模板
        /// </summary>
        /// <param name="sName"></param>
        /// <returns></returns>
        public string GetXmlJavaScriptTpl(string sName)
        {
            StringBuilder sJsTemplate = new StringBuilder("");
            XmlNode xmlNode = XmlJavaScript.SelectSingleNode("//項[@名稱='" + sName + "']");
            if (xmlNode == null)
            {
                throw new Exception("找不到名稱為[" + sName + "]的節點！");
            }
            string sPath = ToolFunc.GetXmlString(xmlNode, "@模版");
            sPath = AppDomain.CurrentDomain.BaseDirectory + sPath;
            using (TextReader sr = File.OpenText(sPath))
            {
                String line;
                while ((line = sr.ReadLine()) != null)
                {
                    sJsTemplate.AppendLine(line);
                }
            }
            return sJsTemplate.ToString();
        }
        public string GetUrlFromJavaScript(string sName)
        {
            string sUrl = "#";
            XmlNode xmlNode = XmlJavaScript.SelectSingleNode("//項[@名稱='" + sName + "']");
            if (xmlNode == null)
            {
                throw new Exception("找不到名稱為[" + sName + "]的節點！");
            }
            XmlElement el = (XmlElement)xmlNode;
            sUrl = el.GetAttribute("Url");
            return sUrl;
        }
        private void LoadXmlProvince()
        {
            string strBasePath = AppDomain.CurrentDomain.BaseDirectory;
            XmlDocument doc = new XmlDocument();
            string sPath = strBasePath + @"Template\" + "Province.Config";
            doc.Load(sPath);
            XmlNode xmlNode = doc.DocumentElement;
            HttpContext.Current.Cache.Insert("province", doc.DocumentElement,
               new CacheDependency(sPath));
        }
        private void LoadXmlJavaScript()
        {
            string strBasePath = AppDomain.CurrentDomain.BaseDirectory;
            XmlDocument doc = new XmlDocument();
            string sPath = strBasePath + @"Template\" + "JavaScript.Config";
            doc.Load(sPath);
            HttpContext.Current.Cache.Insert("javascript", doc.DocumentElement,
                new CacheDependency(sPath));
        }
        private void LoadXmlDimension()
        {
            string strBasePath = AppDomain.CurrentDomain.BaseDirectory;
            XmlDocument doc = new XmlDocument();
            string sPath = strBasePath + @"Template\" + "Dimension.Config";
            doc.Load(sPath);
            HttpContext.Current.Cache.Insert("dimension", doc.DocumentElement,
                new CacheDependency(sPath));
        }
        /// <summary>
        ///
        /// </summary>
        private void LoadXmlQueryList()
        {
            string strBasePath = AppDomain.CurrentDomain.BaseDirectory;
            XmlDocument doc = new XmlDocument();
            string sPath = strBasePath + @"Template\" + "QueryList.config";
            doc.Load(sPath);
            HttpContext.Current.Cache.Insert("querylist", doc.DocumentElement,
                new CacheDependency(sPath));
        }

        /// <summary>
        /// 載入業務對象
        /// </summary>
        private void LoadBusinessObj()
        {
            m_system = new SystemService(this);
            m_order = new OrderService(this);
            m_found = new FoundationService(this);
            m_query = new QueryService(this);
        }

此時可以根據資料庫的角色記錄，通過中繼資料模型進行許可權與模板匹配，從而達到非常棒的架構設計。