求职技术题目收集④ -- 设计模式

一、抽象工厂模式

     去年这个时候，博客园好多关于设计模式的文章，自己也想鼓捣在项目上用个啥模式。当时，学校的服务器没有Sql Server。所有的数据库都是Access，于是就想了工厂模式，最后还是弄成了抽象工厂模式。

     关于抽象工厂的学习一搜一大把，大家可以看园子里朋友的：http://www.cnblogs.com/anlyren/archive/2008/01/31/abstract_factory.html

     我是在一个考试系统中实现了这个模式。

 具体代码

     抽象工厂角色：

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public abstract class AbstractDALFactory    {         static  private string _dbType = ConfigurationManager.AppSettings["DBType"].ToString();    //获得数据库对象实例        static private AbstractDALFactory _instance = null;                 static public AbstractDALFactory Instance        {            get            {                if (_instance == null)                    _instance = (AbstractDALFactory)Activator.CreateInstance(Type.GetType(_dbType));      //利用反射创建数据库对象的实例                return _instance;            }        }                 public abstract ISingleP CreateSingleProblemService();  //创建单选题          public abstract IMultiP CreateMultiProblemService(); //创建多选题          public abstract IJudgeP CreateJudgeProblemService(); //创建判断题      }

 

     单选题接口(抽象产品)：

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public interface ISingleP    {        IList<SingleProblem> GetSingleProblem();          IList<SingleProblem> SelectSingleProblem();          bool InsertSingleProblem(SingleProblem SP);          bool UpdateSingleProblem(SingleProblem sp);          bool DeleteSingleProblem(int SP_ID);          bool ProblemCount(int id);          void AddExcel(string filePath);          SingleProblem GetProblemByID(int id);    }

    SqlServer工厂（具体工厂）：

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public class SqlDALFactory:AbstractDALFactory    {        public override IJudgeP CreateJudgeProblemService()        {            return new JudgeProbmeService();        }          public override ISingleP CreateSingleProblemService()        {            return new SingleProblemService();        }          public override IMultiP CreateMultiProblemService()        {            return new MultiProblemService();        }    }

 

     单选题实现(具体产品)：

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public class SingleProblemService:ISingleP    {        private static string connString = PubConstant.ConnectionString;          public SingleProblemService()        {            //            //TODO: 在此处添加构造函数逻辑            //        }          public IList<SingleProblem> GetSingleProblem()        {               SingleProblem info = new SingleProblem();               return infos;        }          public SingleProblem GetProblemByID(int id)        {            SingleProblem info = new SingleProblem();            return info;        }          public IList<SingleProblem> SelectSingleProblem()        {            IList<SingleProblem> infos = new List<SingleProblem>();            return infos;        }          public bool InsertSingleProblem(SingleProblem SP)        {                return (ret == 1);        }          public bool UpdateSingleProblem(SingleProblem sp)        {                return (ret == 1);        }          public bool DeleteSingleProblem(int SP_ID)        {                    return (ret == 1);        }            public bool ProblemCount(int id)        {                       return (ret == 1);            }        }          public void AddExcel(string filePath)        {        }    }

 

      获取写在web.config中的字串方法：

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public class PubConstant {            /// <summary>     /// 获取连接字符串     /// </summary>     public static string ConnectionString     {                   get         {             string _connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;             string ConStringEncrypt = ConfigurationManager.AppSettings["ConStringEncrypt"];             if (ConStringEncrypt == "true")             {                 _connectionString = DESEncrypt.Decrypt(_connectionString);             }             return _connectionString;         }     } }

 

    web.config配置：

 <appSettings>
  <add key="DBType" value="EO.DAL.DALFactory.SqlDALFactory"/>
  <add key="ConnectionString" value="Data Source=.;Initial Catalog=Photography; User ID=sa;Password="/>
 </appSettings>

 

 业务逻辑层代码（客户端代码）：

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public class SingleProblemManager    {        private static AbstractDALFactory factory = AbstractDALFactory.Instance;        private static ISingleP Isingle = factory.CreateSingleProblemService();          public static IList<SingleProblem> GetSingleProblem()        {            return Isingle.GetSingleProblem();        }          public static IList<SingleProblem> SelectSingleProblem()        {            return Isingle.SelectSingleProblem();        }          public static IList<SingleProblem> GetWrongSingleProblem(int[] ids)        {            IList<SingleProblem> infos = new List<SingleProblem>();            for (int i = 0; i < ids.Length; i++)            {                SingleProblem info = new SingleProblem();                info = Isingle.GetProblemByID(ids[i]);                infos.Add(info);            }            return infos;        }          public static bool UpdateSingleProblem(SingleProblem sp)        {            return Isingle.UpdateSingleProblem(sp);        }          public static bool DeleteSingleProblem(int sp)        {            return Isingle.DeleteSingleProblem(sp);        }          public static bool InsertSingleProblem(SingleProblem sp)        {            return Isingle.InsertSingleProblem(sp);        }          public static bool CountProblem(int id)        {            return Isingle.ProblemCount(id);        }          public static void AddExcel(string filePath)        {            Isingle.AddExcel(filePath);        }    }