原文:
乐在其中设计模式(C#) - 工厂方法模式(Factory Method Pattern)
作者： webabcd
介绍
定义一个用于创建对象的接口，让子类决定将哪一个类实例化。Factory Method使一个类的实例化延迟到其子类。
示例
有SqlMessage和XmlMessage，用Factory Method来实例化它们。
MessageModel
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{
/// <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; }
}
}
}
AbstractMessage
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{
/// <summary>
/// 操作Message抽象类（Product）
/// </summary>
public abstract class AbstractMessage
{
/// <summary>
/// 获取Message
/// </summary>
/// <returns></returns>
public abstract List<MessageModel> Get();
/// <summary>
/// 插入Message
/// </summary>
/// <param name="mm">Message实体对象</param>
/// <returns></returns>
public abstract bool Insert(MessageModel mm);
}
}
SqlMessage
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{
/// <summary>
/// Sql方式操作Message（ConcreteProduct）
/// </summary>
public class SqlMessage : AbstractMessage
{
/// <summary>
/// 获取Message
/// </summary>
/// <returns></returns>
public override 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 override bool Insert(MessageModel mm)
{
// 代码略
return true;
}
}
}
XmlMessage
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{
/// <summary>
/// Xml方式操作Message（ConcreteProduct）
/// </summary>
public class XmlMessage : AbstractMessage
{
/// <summary>
/// 获取Message
/// </summary>
/// <returns></returns>
public override List<MessageModel> Get()
{
List<MessageModel> l = new List<MessageModel>();
l.Add(new MessageModel("XML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 override bool Insert(MessageModel mm)
{
// 代码略
return true;
}
}
}
AbstractMessageFactory
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{
/// <summary>
/// 抽象Message工厂（Creator）
/// </summary>
public abstract class AbstractMessageFactory
{
// An Operation
/// <summary>
/// 工厂方法
/// </summary>
/// <returns>AbstractMessage</returns>
public abstract AbstractMessage CreateMessage();
}
}
SqlMessageFactory
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{
/// <summary>
/// SqlMessage工厂（ConcreteCreator）
/// </summary>
public class SqlMessageFactory : AbstractMessageFactory
{
/// <summary>
/// 实现工厂方法，返回SqlMessage对象
/// </summary>
/// <returns></returns>
public override AbstractMessage CreateMessage()
{
return new SqlMessage();
}
}
}
XmlMessageFactory
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{
/// <summary>
/// XmlMessage工厂（ConcreteCreator）
/// </summary>
public class XmlMessageFactory : AbstractMessageFactory
{
/// <summary>
/// 实现工厂方法，返回XmlMessage对象
/// </summary>
/// <returns></returns>
public override AbstractMessage CreateMessage()
{
return new XmlMessage();
}
}
}
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.FactoryMethod;
public
partial
class
FactoryMethod : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
AbstractMessageFactory amf = new SqlMessageFactory();
AbstractMessage am = amf.CreateMessage();
Response.Write(am.Insert(new MessageModel("插入", DateTime.Now)));
Response.Write("<br />");
Response.Write(am.Get()[0].Message + " " + am.Get()[0].PublishTime.ToString());
Response.Write("<br />");
amf = new XmlMessageFactory();
am = amf.CreateMessage();
Response.Write(am.Insert(new MessageModel("插入", DateTime.Now)));
Response.Write("<br />");
Response.Write(am.Get()[0].Message + " " + am.Get()[0].PublishTime.ToString());
}
}
运行结果
True
SQL方式获取Message 2007-5-4 22:34:39
True
XML方式获取Message 2007-5-4 22:34:39
参考
http://www.dofactory.com/Patterns/PatternFactory.aspx
OK
[源码下载]
乐在其中设计模式(C#) - 工厂方法模式(Factory Method Pattern)
作者： webabcd
介绍
定义一个用于创建对象的接口，让子类决定将哪一个类实例化。Factory Method使一个类的实例化延迟到其子类。
示例
有SqlMessage和XmlMessage，用Factory Method来实例化它们。
MessageModel
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{
/// <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; } } }}
AbstractMessage
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{ /// <summary> /// 操作Message抽象类（Product） /// </summary> public abstract class AbstractMessage { /// <summary> /// 获取Message /// </summary> /// <returns></returns> public abstract List<MessageModel> Get(); /// <summary> /// 插入Message /// </summary> /// <param name="mm">Message实体对象</param> /// <returns></returns> public abstract bool Insert(MessageModel mm); }}
SqlMessage
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{ /// <summary> /// Sql方式操作Message（ConcreteProduct） /// </summary> public class SqlMessage : AbstractMessage { /// <summary> /// 获取Message /// </summary> /// <returns></returns> public override 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 override bool Insert(MessageModel mm) { // 代码略 return true; } }}
XmlMessage
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{ /// <summary> /// Xml方式操作Message（ConcreteProduct） /// </summary> public class XmlMessage : AbstractMessage { /// <summary> /// 获取Message /// </summary> /// <returns></returns> public override List<MessageModel> Get() { List<MessageModel> l = new List<MessageModel>(); l.Add(new MessageModel("XML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 override bool Insert(MessageModel mm) { // 代码略 return true; } }}
AbstractMessageFactory
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{ /// <summary> /// 抽象Message工厂（Creator） /// </summary> public abstract class AbstractMessageFactory { // An Operation /// <summary> /// 工厂方法 /// </summary> /// <returns>AbstractMessage</returns> public abstract AbstractMessage CreateMessage(); }}
SqlMessageFactory
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{ /// <summary> /// SqlMessage工厂（ConcreteCreator） /// </summary> public class SqlMessageFactory : AbstractMessageFactory { /// <summary> /// 实现工厂方法，返回SqlMessage对象 /// </summary> /// <returns></returns> public override AbstractMessage CreateMessage() { return new SqlMessage(); } }}
XmlMessageFactory
using
System;
using
System.Collections.Generic;
using
System.Text;
namespace
Pattern.FactoryMethod
{ /// <summary> /// XmlMessage工厂（ConcreteCreator） /// </summary> public class XmlMessageFactory : AbstractMessageFactory { /// <summary> /// 实现工厂方法，返回XmlMessage对象 /// </summary> /// <returns></returns> public override AbstractMessage CreateMessage() { return new XmlMessage(); } }}
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.FactoryMethod;
public
partial
class
FactoryMethod : System.Web.UI.Page
{ protected void Page_Load(object sender, EventArgs e) { AbstractMessageFactory amf = new SqlMessageFactory(); AbstractMessage am = amf.CreateMessage(); Response.Write(am.Insert(new MessageModel("插入", DateTime.Now))); Response.Write("<br />"); Response.Write(am.Get()[0].Message + " " + am.Get()[0].PublishTime.ToString()); Response.Write("<br />"); amf = new XmlMessageFactory(); am = amf.CreateMessage(); Response.Write(am.Insert(new MessageModel("插入", DateTime.Now))); Response.Write("<br />"); Response.Write(am.Get()[0].Message + " " + am.Get()[0].PublishTime.ToString()); }}
运行结果
True
SQL方式获取Message 2007-5-4 22:34:39
True
XML方式获取Message 2007-5-4 22:34:39
参考
http://www.dofactory.com/Patterns/PatternFactory.aspx
OK
[源码下载]
