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
{
/// <summary>
/// Message实体类
/// </summary>
public class MessageModel
{
/// <summary>
/// 构造函数
/// </summary>
/// <param name="msg">Message内容</param>
/// <param name="pt">Message发布时间</param>
public MessageModel(string msg, DateTime pt)
{
this._message = msg;
this._publishTime = pt;
} private string _message;
/// <summary>
/// Message内容
/// </summary>
public string Message
{
get { return _message; }
set { _message = value; }
} private DateTime _publishTime;
/// <summary>
/// Message发布时间
/// </summary>
public DateTime PublishTime
{
get { return _publishTime; }
set { _publishTime = value; }
}
}
}
IMessage
using System;
using System.Collections.Generic;
using System.Text; namespace Pattern.Proxy
{
/// <summary>
/// 对Message操作的接口
/// </summary>
public interface IMessage
{
/// <summary>
/// 获取Message
/// </summary>
/// <returns></returns>
List<MessageModel> Get(); /// <summary>
/// 插入Message
/// </summary>
/// <param name="mm">Message实体对象</param>
/// <returns></returns>
bool Insert(MessageModel mm);
}
}
SqlMessage
using System;
using System.Collections.Generic;
using System.Text; namespace Pattern.Proxy
{
/// <summary>
/// Sql方式操作Message
/// </summary>
public class SqlMessage : IMessage
{
/// <summary>
/// 获取Message
/// </summary>
/// <returns></returns>
public List<MessageModel> Get()
{
List<MessageModel> l = new List<MessageModel>();
l.Add(new MessageModel("SQL方式获取Message", DateTime.Now)); return l;
} /// <summary>
/// 插入Message
/// </summary>
/// <param name="mm">Message实体对象</param>
/// <returns></returns>
public bool Insert(MessageModel mm)
{
// 代码略
return true;
}
}
}
MessageProxy
using System;
using System.Collections.Generic;
using System.Text; namespace Pattern.Proxy
{
/// <summary>
/// 代理类
/// </summary>
public class MessageProxy : IMessage
{
SqlMessage _sqlMessage; /// <summary>
/// 构造函数
/// </summary>
public MessageProxy()
{
_sqlMessage = new SqlMessage();
} /// <summary>
/// 获取Message
/// </summary>
/// <returns></returns>
public List<MessageModel> Get()
{
return _sqlMessage.Get();
} /// <summary>
/// 插入Message
/// </summary>
/// <param name="mm">Message实体对象</param>
/// <returns></returns>
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("<br />");
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