用反射机制实例化工厂实现数据库操作

 

using System;
using System.Collections.Generic;
using System.Text;
using System.Configuration;
using System.Data.Common;

namespace DataAccess
{
    //
    // 根据要求取得具体品牌的产品，读取配置文件，用反射机制实例化具体的工厂，并获取具体产品
    //
    class DbManager
    {
        DBManagerAbstractFactory dBManagerAbstractFactory =   null ;
        string dbType =   "" ;
        string connectionText = "" ;


        //
        // 构造方法，读取工厂名字和数据库连接文本，用反射机制实例化具体的工厂
        //
        public DbManager()
        {
            dbType = ConfigurationSettings.AppSettings[ " dbType " ]; // 读取配置文件
            connectionText = ConfigurationSettings.AppSettings[ " connectionText " ]; // 读取配置文件

            try
            {
                Type type = Type.GetType(dbType, true ); // 通过类名获取类
                dBManagerAbstractFactory = (DBManagerAbstractFactory)Activator.CreateInstance(type); // 反射机智实例化具体工厂
            }
            catch (TypeLoadException e)
            {
                Console.WriteLine(e.Message);
            }

        }

        public DbConnection GetConnection()
        {
            DbConnection con = dBManagerAbstractFactory.GetConnection();
            con.ConnectionString = connectionText;
            return con;
        }
        public DbDataAdapter GetDataAdapter()
        {
            return dBManagerAbstractFactory.GetDataAdapter();
        }
         
        
    }
}