代理模式(Proxy Pattern)

 

介绍

为其他对象提供一个代理以控制对这个对象的访问。

示例

有一个Message实体类，某对象对它的操作有Insert()和Get()方法，用一个代理来控制对这个对象的访问。

　　MessageModel

using System;using System.Collections.Generic;using System.Text;namespace Pattern.Proxy{    /// 
    /// Message实体类    /// 
    public class MessageModel    {        /// 
        /// 构造函数        /// 
        /// Message内容        /// Message发布时间        public MessageModel(string msg, DateTime pt)        {            this._message = msg;            this._publishTime = pt;        }        private string _message;        /// 
        /// Message内容        /// 
        public string Message        {            get { return _message; }            set { _message = value; }        }        private DateTime _publishTime;        /// 
        /// Message发布时间        /// 
        public DateTime PublishTime        {            get { return _publishTime; }            set { _publishTime = value; }        }    }}

　　IMessage

using System;using System.Collections.Generic;using System.Text;namespace Pattern.Proxy{    /// 
    /// 对Message操作的接口    /// 
    public interface IMessage    {        /// 
        /// 获取Message        /// 
        /// 
             List
     
       Get();        /// 
      
        /// 插入Message        /// 
        /// 
      Message实体对象        /// 
              bool Insert(MessageModel mm);    }}
     

　　SqlMessage

using System;using System.Collections.Generic;using System.Text;namespace Pattern.Proxy{    /// 
    /// Sql方式操作Message    /// 
    public class SqlMessage : IMessage    {        /// 
        /// 获取Message        /// 
        /// 
             public List
     
       Get()        {            List
      
        l = new List
       
        ();            l.Add(new MessageModel("SQL方式获取Message", DateTime.Now));            return l;        }        /// 
        
        /// 插入Message        /// 
        /// 
        Message实体对象        /// 
                public bool Insert(MessageModel mm)        {            // 代码略            return true;        }    }}
       
      
     

　　MessageProxy

using System;using System.Collections.Generic;using System.Text;namespace Pattern.Proxy{    /// 
    /// 代理类    /// 
    public class MessageProxy : IMessage    {        SqlMessage _sqlMessage;        /// 
        /// 构造函数        /// 
        public MessageProxy()        {            _sqlMessage = new SqlMessage();        }        /// 
        /// 获取Message        /// 
        /// 
             public List
     
       Get()        {            return _sqlMessage.Get();        }        /// 
      
        /// 插入Message        /// 
        /// 
      Message实体对象        /// 
              public bool Insert(MessageModel mm)        {            return _sqlMessage.Insert(mm);        }    }}
     

　　Client

using System;using System.Data;using System.Configuration;using System.Collections;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;using Pattern.Proxy;public partial class Proxy : System.Web.UI.Page{    protected void Page_Load(object sender, EventArgs e)    {        MessageProxy m = new MessageProxy();        Response.Write(m.Insert(new MessageModel("插入", DateTime.Now)));        Response.Write("
");        Response.Write(m.Get()[0].Message + " " + m.Get()[0].PublishTime.ToString());    }}

　　运行结果

　　True

　　SQL方式获取Message 2007-4-1 16:31:24