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乐在其中设计模式(C#) - 建造者模式(Builder Pattern)

Posted on 2007-05-05 20:56  webabcd  阅读(6968)  评论(45编辑  收藏
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乐在其中设计模式(C#) - 建造者模式(Builder Pattern)


作者:webabcd


介绍
将一个复杂对象的构建与它的表示分离,使得同样的构建过程可以创建不同的表示。


示例
用同样的构建过程创建Sql和Xml的Insert()方法和Get()方法。



MessageModel
using System;
using System.Collections.Generic;
using System.Text;

namespace Pattern.Builder
{
    
/// <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; }
        }

    }

}


SqlMessage
using System;
using System.Collections.Generic;
using System.Text;

namespace Pattern.Builder
{
    
/// <summary>
    
/// Sql方式操作Message
    
/// </summary>

    public class SqlMessage
    
{
        
/// <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;
        }

    }

}


XmlMessage
using System;
using System.Collections.Generic;
using System.Text;

namespace Pattern.Builder
{
    
/// <summary>
    
/// Xml方式操作Message
    
/// </summary>

    public class XmlMessage
    
{
        
/// <summary>
        
/// 获取Message
        
/// </summary>
        
/// <returns></returns>

        public 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 bool Insert(MessageModel mm)
        
{
            
// 代码略
            return true;
        }

    }

}


Operation
using System;
using System.Collections.Generic;
using System.Text;

using System.Reflection;

namespace Pattern.Builder
{
    
/// <summary>
    
/// 操作(Product)
    
/// </summary>

    public class Operation
    
{
        
private string _type;
        
private Dictionary<stringstring> _dictionary;

        
/// <summary>
        
/// 构造函数
        
/// </summary>
        
/// <param name="type">产品类型</param>

        public Operation(string type)
        
{
            _dictionary 
= new Dictionary<stringstring>();
            
this._type = type;
        }


        
/// <summary>
        
/// 索引器
        
/// </summary>
        
/// <param name="key"></param>
        
/// <returns></returns>

        public string this[string key]
        
{
            
get return _dictionary[key]; }
            
set { _dictionary[key] = value; }
        }


        
/// <summary>
        
/// 获得结果
        
/// </summary>
        
/// <returns></returns>

        public string GetResult()
        
{
            Assembly assembly 
= Assembly.Load("Pattern.Builder");

            MethodInfo methodGet 
= assembly.GetType("Pattern.Builder." + _dictionary["get"].Split('|')[0]).GetMethod(_dictionary["get"].Split('|')[1]);
            
object objGet = methodGet.Invoke(assembly.CreateInstance("Pattern.Builder." + _dictionary["get"].Split('|')[0]), null);
            List
<MessageModel> m = (List<MessageModel>)objGet;
            
            MethodInfo methodInsert 
= assembly.GetType("Pattern.Builder." + _dictionary["insert"].Split('|')[0]).GetMethod(_dictionary["insert"].Split('|')[1]);
            
object objInsert = methodInsert.Invoke(assembly.CreateInstance("Pattern.Builder." + _dictionary["insert"].Split('|')[0]), new object[] new MessageModel(_dictionary["insert"].Split('|')[2], Convert.ToDateTime(_dictionary["insert"].Split('|')[3])) });
            
bool b = (bool)objInsert;

            
return "类型为" + this._type + "的执行结果:<br />" + b.ToString() + "<br />" + m[0].Message + " " + m[0].PublishTime.ToString() + "<br />";
        }

    }

}


AbstractMessageBuilder
using System;
using System.Collections.Generic;
using System.Text;

namespace Pattern.Builder
{
    
/// <summary>
    
/// 抽象Message建造者(Builder)
    
/// </summary>

    public abstract class AbstractMessageBuilder
    
{
        
/// <summary>
        
/// 构造函数
        
/// </summary>
        
/// <param name="type">产品类型</param>

        public AbstractMessageBuilder(string type)
        
{
            
this._operation = new Operation(type);
        }


        
/// <summary>
        
/// 操作(Product)
        
/// </summary>

        protected Operation _operation;
        
/// <summary>
        
/// 操作(Product)
        
/// </summary>

        public Operation Operation
        
{
            
get return _operation; }
            
set { _operation = value; }
        }


        
/// <summary>
        
/// 建造插入方法
        
/// </summary>
        
/// <param name="mm"></param>

        abstract public void BuilderInsert(MessageModel mm);

        
/// <summary>
        
/// 建造获取方法
        
/// </summary>

        abstract public void BuilderGet();
    }

}


SqlMessageBuilder
using System;
using System.Collections.Generic;
using System.Text;

namespace Pattern.Builder
{
    
/// <summary>
    
/// SqlMessage建造者(ConcreteBuilder)
    
/// </summary>

    public class SqlMessageBuilder : AbstractMessageBuilder
    
{
        
/// <summary>
        
/// 构造函数
        
/// </summary>

        public SqlMessageBuilder()
            : 
base("sql")
        
{
 
        }


        
/// <summary>
        
/// 建造Sql插入方法
        
/// </summary>
        
/// <param name="mm">Message实体对象</param>

        public override void BuilderInsert(MessageModel mm)
        
{
            
base._operation["insert"= "SqlMessage|Insert|" + mm.Message + "|" + mm.PublishTime.ToString() + "";
        }


        
/// <summary>
        
/// 建造Sql获取方法
        
/// </summary>

        public override void BuilderGet()
        
{
            
base._operation["get"= "SqlMessage|Get";
        }

    }

}


XmlMessageBuilder
using System;
using System.Collections.Generic;
using System.Text;

namespace Pattern.Builder
{
    
/// <summary>
    
/// XmlMessage建造者(ConcreteBuilder)
    
/// </summary>

    public class XmlMessageBuilder : AbstractMessageBuilder
    
{
        
/// <summary>
        
/// 构造函数
        
/// </summary>

        public XmlMessageBuilder()
            : 
base("xml")
        
{
 
        }


        
/// <summary>
        
/// 建造Xml插入方法
        
/// </summary>
        
/// <param name="mm">Message实体对象</param>

        public override void BuilderInsert(MessageModel mm)
        
{
            
base._operation["insert"= "XmlMessage|Insert|"+mm.Message+"|"+mm.PublishTime.ToString()+"";
        }


        
/// <summary>
        
/// 建造Xml获取方法
        
/// </summary>

        public override void BuilderGet()
        
{
            
base._operation["get"= "XmlMessage|Get";
        }

    }

}


Message
using System;
using System.Collections.Generic;
using System.Text;

namespace Pattern.Builder
{
    
/// <summary>
    
/// 指导者(Director)
    
/// </summary>

    public class Message
    
{
        
/// <summary>
        
/// 调用具体建造者角色以创建产品对象
        
/// </summary>
        
/// <param name="messageBuilder">AbstractMessageBuilder</param>
        
/// <param name="mm">Message实体对象</param>

        public void Construct(AbstractMessageBuilder messageBuilder, MessageModel mm)
        
{
            messageBuilder.BuilderInsert(mm);
            messageBuilder.BuilderGet();
        }

    }

}



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.Builder;

public partial class Builder : System.Web.UI.Page
{
    
protected void Page_Load(object sender, EventArgs e)
    
{
        Message m 
= new Message();

        AbstractMessageBuilder amb 
= new SqlMessageBuilder();
        m.Construct(amb, 
new MessageModel("插入", DateTime.Now));

        Response.Write(amb.Operation.GetResult());

        amb 
= new XmlMessageBuilder();
        m.Construct(amb, 
new MessageModel("插入", DateTime.Now));

        Response.Write(amb.Operation.GetResult());
    }

}


运行结果
类型为sql的执行结果:
True
SQL方式获取Message 2007-5-5 20:53:28
类型为xml的执行结果:
True
XML方式获取Message 2007-5-5 20:53:28


参考
http://www.dofactory.com/Patterns/PatternBuilder.aspx


OK
[源码下载]