极速理解设计模式系列:12.责任链模式(Chain of Responsibility Pattern)

四个角色:传递者接口(Handler)、具体传递者(ConcreteHandler)、客户端(Client) 

        传递者接口(Handler):定义一个处理请求的接口和实现下一个对象

        具体传递者(ConcreteHandler):如果能够处理就处理,否则让上级处理请求

        客户端(Client) :创立责任链,并向链中对象提出请求

 实现思路:传递者接口设置上级然后提供一个处理请求的方法,在具体传递中如果能够处理就处理,否则就让其上级来处理,客户端组织其责任链,并且设置请求。

 类图:

 

应用场景:OA系统中的请假审批系统,普通开发者想请假,如果请1天及以下的假则只需要开发经理许可,如果1天<请假天数<=5天则需要总监许可,如果5天<请假天数<=10天则需要副总裁批准,如果请假天数>10天则需要总裁许可。

分析:在客户端设置责任链和请假审批的上级下级,然后每次普通开发者将请假申请提交到开发经理,如果在开发经理许可范围之内,则处理,否则提交给他的上级总监,以此类推处理这个请假请求。

        下面我们在控制台程序去演示一下如何使用Chain of Responsibility Pattern:

        一、 传递者接口(Handler)

    //传递者接口(Handler)
abstract class Higher
{
public string Name { get; set; }
public Higher higher;
public void SetHigher(Higher _Higher)
{
this.higher = _Higher;
}
public Higher(string name)
{
Name = name;
}
public abstract void ExeApply(Apply apply);
}

        二、具体传递者(ConcreteHandler)

    //具体传递者(ConcreteHandler)
class ManagerHigher : Higher
{
public ManagerHigher(string name) : base(name) { }
public override void ExeApply(Apply apply)
{
if (apply.ApplyDay <= 1)
Console.WriteLine(Name + " 批准 " + apply.ApplyName + " 申请了 " + apply.ApplyDay + "天假期");
else
higher.ExeApply(apply);
}
}

//具体传递者(ConcreteHandler)
class DirectorHigher : Higher
{
public DirectorHigher(string name) : base(name) { }
public override void ExeApply(Apply apply)
{
if (apply.ApplyDay <= 5)
Console.WriteLine(Name + " 批准 " + apply.ApplyName + " 申请了 " + apply.ApplyDay + "天假期");
else
higher.ExeApply(apply);
}
}

//具体传递者(ConcreteHandler)
class VPHigher : Higher
{
public VPHigher(string name) : base(name) { }
public override void ExeApply(Apply apply)
{
if (apply.ApplyDay <= 10)
Console.WriteLine(Name + " 批准 " + apply.ApplyName + " 申请了 " + apply.ApplyDay + "天假期");
else
higher.ExeApply(apply);
}
}

//具体传递者(ConcreteHandler)
class CEOHigher : Higher
{
public CEOHigher(string name) : base(name) { }
public override void ExeApply(Apply apply)
{
if (apply.ApplyDay>10)
Console.WriteLine(Name + " 批准 " + apply.ApplyName + " 申请了 " + apply.ApplyDay + "天假期");
else
higher.ExeApply(apply);
}
}

        三、客户端(Client)

    class Program
{
static void Main(string[] args)
{
//责任链模式的创建
Higher managerHigher = new ManagerHigher("张三经理");
Higher directorHigher = new DirectorHigher("李四总监");
Higher vpHigher = new VPHigher("王五副总裁");
Higher ceoHigher = new CEOHigher("林一总裁");
managerHigher.SetHigher(directorHigher);
directorHigher.SetHigher(vpHigher);
vpHigher.SetHigher(ceoHigher);

//创建申请人
Apply liuying = new Apply() { ApplyName = "刘颖", ApplyDay = 5 };
Apply chenming = new Apply() { ApplyName = "陈明", ApplyDay = 1 };
Apply zengli = new Apply() { ApplyName = "曾利", ApplyDay = 15 };

//申请人都将申请提交给经理
managerHigher.ExeApply(liuying);
managerHigher.ExeApply(chenming);
managerHigher.ExeApply(zengli);

Console.ReadLine();
}
}

        申请人

    //申请人
class Apply
{
public string ApplyName { get; set; }
public double ApplyDay { get; set; }
}

        如需源码请点击 ResponsibilityPattern.rar  下载。

posted @ 2011-10-08 10:51 程兴亮 阅读(...) 评论(...) 编辑 收藏