using System;
using System.Reflection;
using System.Configuration;
using NETManage.IDAL;
namespace NETManage.DALFactory
{
	/// <summary>
	/// 抽象工廠模式創(chuàng)建DAL。
	/// web.config 需要加入配置：(利用工廠模式+反射機(jī)制+緩存機(jī)制,實(shí)現(xiàn)動(dòng)態(tài)創(chuàng)建不同的數(shù)據(jù)層對(duì)象接口)  
	/// DataCache類(lèi)在導(dǎo)出代碼的文件夾里
	/// 可以把所有DAL類(lèi)的創(chuàng)建放在這個(gè)DataAccess類(lèi)里
	/// <appSettings>  
    /// <add key="WebDAL" value="NETManage.SQLServerDAL" /> (這里的命名空間根據(jù)實(shí)際情況更改為自己項(xiàng)目的命名空間)
	/// </appSettings> 
	/// </summary>
	public sealed class DataAccess
	{
        private static readonly string path = ConfigurationManager.AppSettings["WebDAL"];
		/// <summary>
		/// 創(chuàng)建對(duì)象或從緩存獲取
		/// </summary>
		public static object CreateObject(string path,string CacheKey)
		{
			object objType = DataCache.GetCache(CacheKey);//從緩存讀取
			if (objType == null)
			{
				try
				{
					objType = Assembly.Load(path).CreateInstance(CacheKey);//反射創(chuàng)建
					DataCache.SetCache(CacheKey, objType);// 寫(xiě)入緩存
				}
				catch
				{}
			}
			return objType;
		}
		/// <summary>
		/// 創(chuàng)建Manager數(shù)據(jù)層接口
		/// </summary>
		public static NETManage.IDAL.IManager CreateManager()
		{

			string CacheKey = path+".Manager";
			object objType=CreateObject(path,CacheKey);
			return (NETManage.IDAL.IManager)objType;
		}

		/// <summary>
		/// 創(chuàng)建OnlinePC數(shù)據(jù)層接口
		/// </summary>
		public static NETManage.IDAL.IOnlinePC CreateOnlinePC()
		{

			string CacheKey = path+".OnlinePC";
			object objType=CreateObject(path,CacheKey);
			return (NETManage.IDAL.IOnlinePC)objType;
		}

}
}