乐在其中设计模式(C#) - 装饰模式(Decorator Pattern)
[索引页]
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作者： webabcd
介绍
动态地给一个对象添加一些额外的职责。就扩展功能而言，它比生成子类方式更为灵活。
示例
有一个Message实体类，某个对象对它的操作有Insert()和Get()方法，现在扩展这个对象的功能。
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.Decorator
{
/// <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; }
}
}
}
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.Decorator
{
/// <summary>
/// 操作Message的抽象构件（Component）
/// </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);
}
}
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.Decorator
{
/// <summary>
/// Sql方式操作Message（ConcreteComponent）
/// </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;
}
}
}
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.Decorator
{
/// <summary>
/// Xml方式操作Message（ConcreteComponent）
/// </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;
}
}
}
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.Decorator
{
/// <summary>
/// 装饰AbstractMessage（Decorator）
/// </summary>
public
abstract
class AbstractMessageWrapper : AbstractMessage
{
private AbstractMessage _abstractMessage;
/// <summary>
/// 构造函数
/// </summary>
/// <param name="abstractMessage">AbstractMessage</param>
public AbstractMessageWrapper(AbstractMessage abstractMessage)
{
this._abstractMessage = abstractMessage;
}
/// <summary>
/// 获取Message
/// </summary>
/// <returns></returns>
public
override List<MessageModel> Get()
{
return _abstractMessage.Get();
}
/// <summary>
/// 插入Message
/// </summary>
/// <param name="mm">Message实体对象</param>
/// <returns></returns>
public
override
bool Insert(MessageModel mm)
{
return _abstractMessage.Insert(mm);
}
}
}
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.Decorator
{
/// <summary>
/// 扩展出用户验证的功能（ConcreteDecorator）
/// </summary>
public
class CheckUserWrapper : AbstractMessageWrapper
{
/// <summary>
/// 构造函数
/// </summary>
/// <param name="abstractMessage">AbstractMessage</param>
public CheckUserWrapper(AbstractMessage abstractMessage)
:
base(abstractMessage)
{
}
/// <summary>
/// 获取Message
/// </summary>
/// <returns></returns>
public
override List<MessageModel> Get()
{
List<MessageModel> l =
base.Get();
foreach (MessageModel mm
in l)
{
mm.Message +=
"（经过用户验证）";
}
return l;
}
/// <summary>
/// 插入Message
/// </summary>
/// <param name="mm">Message实体对象</param>
/// <returns></returns>
public
override
bool Insert(MessageModel mm)
{
// 在这里扩展功能
return
base.Insert(mm);
}
}
}
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.Decorator
{
/// <summary>
/// 扩展出输入验证的功能（ConcreteDecorator）
/// </summary>
public
class CheckInputWrapper : AbstractMessageWrapper
{
/// <summary>
/// 构造函数
/// </summary>
/// <param name="abstractMessage">AbstractMessage</param>
public CheckInputWrapper(AbstractMessage abstractMessage)
:
base(abstractMessage)
{
}
/// <summary>
/// 获取Message
/// </summary>
/// <returns></returns>
public
override List<MessageModel> Get()
{
List<MessageModel> l =
base.Get();
foreach (MessageModel mm
in l)
{
mm.Message +=
"（经过输入验证）";
}
return l;
}
/// <summary>
/// 插入Message
/// </summary>
/// <param name="mm">Message实体对象</param>
/// <returns></returns>
public
override
bool Insert(MessageModel mm)
{
// 在这里扩展功能
return
base.Insert(mm);
}
}
}
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.Decorator;
public partial
class Decorator : System.Web.UI.Page
{
protected
void Page_Load(
object sender, EventArgs e)
{
AbstractMessage message =
new SqlMessage();
AbstractMessageWrapper amr =
new CheckUserWrapper(message);
Response.Write(amr.Get()[0].Message +
" " + amr.Get()[0].PublishTime.ToString());
Response.Write(
"<br />");
AbstractMessageWrapper amr2 =
new CheckInputWrapper(message);
Response.Write(amr2.Get()[0].Message +
" " + amr2.Get()[0].PublishTime.ToString());
Response.Write(
"<br />");
AbstractMessageWrapper amr3 =
new CheckUserWrapper(message);
AbstractMessageWrapper amr4 =
new CheckInputWrapper(amr3);
Response.Write(amr4.Get()[0].Message +
" " + amr4.Get()[0].PublishTime.ToString());
Response.Write(
"<br />");
}
}
运行结果
SQL方式获取Message（经过用户验证） 2007-5-13 19:34:01
SQL方式获取Message（经过输入验证） 2007-5-13 19:34:01
SQL方式获取Message（经过用户验证）（经过输入验证） 2007-5-13 19:34:01
参考
http://www.dofactory.com/Patterns/PatternDecorator.aspx
OK
[×××]
[×××]
乐在其中设计模式(C#) - 装饰模式(Decorator Pattern)
作者： webabcd
介绍
动态地给一个对象添加一些额外的职责。就扩展功能而言，它比生成子类方式更为灵活。
示例
有一个Message实体类，某个对象对它的操作有Insert()和Get()方法，现在扩展这个对象的功能。
MessageModel
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.Decorator
{
/// <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.Decorator
{
/// <summary>
/// 操作Message的抽象构件（Component）
/// </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.Decorator
{
/// <summary>
/// Sql方式操作Message（ConcreteComponent）
/// </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.Decorator
{
/// <summary>
/// Xml方式操作Message（ConcreteComponent）
/// </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;
}
}
}
AbstractMessageWrapper
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.Decorator
{
/// <summary>
/// 装饰AbstractMessage（Decorator）
/// </summary>
public
abstract
class AbstractMessageWrapper : AbstractMessage
{
private AbstractMessage _abstractMessage;
/// <summary>
/// 构造函数
/// </summary>
/// <param name="abstractMessage">AbstractMessage</param>
public AbstractMessageWrapper(AbstractMessage abstractMessage)
{
this._abstractMessage = abstractMessage;
}
/// <summary>
/// 获取Message
/// </summary>
/// <returns></returns>
public
override List<MessageModel> Get()
{
return _abstractMessage.Get();
}
/// <summary>
/// 插入Message
/// </summary>
/// <param name="mm">Message实体对象</param>
/// <returns></returns>
public
override
bool Insert(MessageModel mm)
{
return _abstractMessage.Insert(mm);
}
}
}
CheckUserWrapper
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.Decorator
{
/// <summary>
/// 扩展出用户验证的功能（ConcreteDecorator）
/// </summary>
public
class CheckUserWrapper : AbstractMessageWrapper
{
/// <summary>
/// 构造函数
/// </summary>
/// <param name="abstractMessage">AbstractMessage</param>
public CheckUserWrapper(AbstractMessage abstractMessage)
:
base(abstractMessage)
{
}
/// <summary>
/// 获取Message
/// </summary>
/// <returns></returns>
public
override List<MessageModel> Get()
{
List<MessageModel> l =
base.Get();
foreach (MessageModel mm
in l)
{
mm.Message +=
"（经过用户验证）";
}
return l;
}
/// <summary>
/// 插入Message
/// </summary>
/// <param name="mm">Message实体对象</param>
/// <returns></returns>
public
override
bool Insert(MessageModel mm)
{
// 在这里扩展功能
return
base.Insert(mm);
}
}
}
CheckInputWrapper
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.Decorator
{
/// <summary>
/// 扩展出输入验证的功能（ConcreteDecorator）
/// </summary>
public
class CheckInputWrapper : AbstractMessageWrapper
{
/// <summary>
/// 构造函数
/// </summary>
/// <param name="abstractMessage">AbstractMessage</param>
public CheckInputWrapper(AbstractMessage abstractMessage)
:
base(abstractMessage)
{
}
/// <summary>
/// 获取Message
/// </summary>
/// <returns></returns>
public
override List<MessageModel> Get()
{
List<MessageModel> l =
base.Get();
foreach (MessageModel mm
in l)
{
mm.Message +=
"（经过输入验证）";
}
return l;
}
/// <summary>
/// 插入Message
/// </summary>
/// <param name="mm">Message实体对象</param>
/// <returns></returns>
public
override
bool Insert(MessageModel mm)
{
// 在这里扩展功能
return
base.Insert(mm);
}
}
}
Test
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.Decorator;
public partial
class Decorator : System.Web.UI.Page
{
protected
void Page_Load(
object sender, EventArgs e)
{
AbstractMessage message =
new SqlMessage();
AbstractMessageWrapper amr =
new CheckUserWrapper(message);
Response.Write(amr.Get()[0].Message +
" " + amr.Get()[0].PublishTime.ToString());
Response.Write(
"<br />");
AbstractMessageWrapper amr2 =
new CheckInputWrapper(message);
Response.Write(amr2.Get()[0].Message +
" " + amr2.Get()[0].PublishTime.ToString());
Response.Write(
"<br />");
AbstractMessageWrapper amr3 =
new CheckUserWrapper(message);
AbstractMessageWrapper amr4 =
new CheckInputWrapper(amr3);
Response.Write(amr4.Get()[0].Message +
" " + amr4.Get()[0].PublishTime.ToString());
Response.Write(
"<br />");
}
}
运行结果
SQL方式获取Message（经过用户验证） 2007-5-13 19:34:01
SQL方式获取Message（经过输入验证） 2007-5-13 19:34:01
SQL方式获取Message（经过用户验证）（经过输入验证） 2007-5-13 19:34:01
参考
http://www.dofactory.com/Patterns/PatternDecorator.aspx
OK
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转载于:https://blog.51cto.com/webabcd/344533