[索引页]
[源码下载]乐在其中设计模式(C#) - 责任链模式(Chain of Responsibility Pattern)
作者：
webabcd
介绍
为解除请求的发送者和接收者之间耦合，而使多个对象都有机会处理这个请求。将这些对象连成一条链，并沿着这条链传递该请求，直到有一个对象处理它。
示例
有一个Message实体类，某个类对它的操作有Insert()方法。现在要求根据插入信息的字符长度，让不同的对象去处理，这些对象连成一条链，并沿着这条链传递该请求，直到有一个对象处理它。
MessageModel
SqlMessage
AbstractExecutor
Employee
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.ChainOfResponsibility
{
/// <summary> /// 具体处理者(ConcreteHandler)角色 /// </summary> public class Employee : AbstractExecutor
{
/// <summary> /// 插入Message /// </summary> /// <param name="mm">Message实体对象</param> /// <returns>执行者；内容；时间</returns> public override string Insert(MessageModel mm)
{
string rtn = "";
// 插入的信息字符数小于5 if (mm.Message.Length < 5)
{
SqlMessage m =
new SqlMessage();
if (m.Insert(mm))
{
rtn =
"执行者：雇员" +
" 内容：" + mm.Message +
" 时间：" + mm.PublishTime.ToString();
}
}
// 否则让上级去执行 else if (
base._executor !=
null)
{
rtn = _executor.Insert(mm);
}
return rtn;
}
}
}
Leader
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.ChainOfResponsibility
{
/// <summary> /// 抽象处理者(Handler)角色 /// </summary> public class Leader : AbstractExecutor
{
/// <summary> /// 插入Message /// </summary> /// <param name="mm">Message实体对象</param> /// <returns>执行者；内容；时间</returns> public override string Insert(MessageModel mm)
{
string rtn = "";
// 插入的信息字符数小于10 if (mm.Message.Length < 10)
{
SqlMessage m =
new SqlMessage();
if (m.Insert(mm))
{
rtn =
"执行者：主管" +
" 内容：" + mm.Message +
" 时间：" + mm.PublishTime.ToString();
}
}
// 否则让上级去执行 else if (
base._executor !=
null)
{
rtn = _executor.Insert(mm);
}
return rtn;
}
}
}
Manager
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.ChainOfResponsibility
{
/// <summary> /// 抽象处理者(Handler)角色 /// </summary> public class Manager : AbstractExecutor
{
/// <summary> /// 插入Message /// </summary> /// <param name="mm">Message实体对象</param> /// <returns>执行者；内容；时间</returns> public override string Insert(MessageModel mm)
{
string rtn = "";
// 插入的信息字符数小于15 if (mm.Message.Length < 15)
{
SqlMessage m =
new SqlMessage();
if (m.Insert(mm))
{
rtn =
"执行者：经理" +
" 内容：" + mm.Message +
" 时间：" + mm.PublishTime.ToString();
}
}
else {
rtn =
"你所插入的Message不符合要求";
}
return rtn;
}
}
}
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.ChainOfResponsibility;
public partial
class ChainOfResponsibility : System.Web.UI.Page
{
protected void Page_Load(
object sender, EventArgs e)
{
AbstractExecutor employee =
new Employee();
AbstractExecutor leader =
new Leader();
AbstractExecutor manager =
new Manager();
employee.SetSuccessor(leader);
leader.SetSuccessor(manager);
Response.Write(employee.Insert(
new MessageModel(
"abcd", DateTime.Now)));
Response.Write(
"<br />");
Response.Write(employee.Insert(
new MessageModel(
"abcdefgh", DateTime.Now)));
Response.Write(
"<br />");
Response.Write(employee.Insert(
new MessageModel(
"abcdefghigkl", DateTime.Now)));
Response.Write(
"<br />");
Response.Write(employee.Insert(
new MessageModel(
"abcdefghigklmnop", DateTime.Now)));
}
}
本文转自webabcd 51CTO博客，原文链接：http://blog.51cto.com/webabcd/344543，如需转载请自行联系原作者