设计模式-责任链设计模式

责任链设计模式，是行为型设计模式的巅峰之作。

现在有一个场景，请假申请。请假时间的长短，需要不同级别的领导才能审批。

万物皆对象嘛，请假需要工号、姓名、原因、时长、结果等等，那我们来定义一个请假的类。其实其就是一个上下文环境（context），保存业务处理中参数-----中间结果-----最终结果。行为型设计模式重用的标配，把行为转移。

public class applycontext
{
    public int id { get; set; }
    public string name { get; set; }
    /// <summary>
    /// 请假时长
    /// </summary>
    public int hour { get; set; }
    public string description { get; set; }
    public bool auditresult { get; set; }
    public string auditremark { get; set; }
}

请假需要new一个实例：

 applycontext context = new applycontext()
 {
     id = 506,
     name = "bingle",
     hour = 100,
     description = "世界那么大，我想去看看！",
     auditresult = false,
     auditremark = ""
 };

第一种方式，审批逻辑都卸载上端，直接就是需求翻译，没有任何加工，谈不上什么扩展，面向国产：

 if (context.hour <= 8)
 {
     console.writeline("pm审批通过");
 }
 else if (context.hour <= 16)
 {
     console.writeline("主管审批通过");
 }
 else
 {
     console.writeline("************");
 }

第二种方式，面向对象：封装--继承--多态，转移业务逻辑，也只是一个翻译机，翻译完+面向对象，其实完全没有涉及加工没有思考。

领导类s：

 public class pm
 {
     public override void audit(applycontext context)
     {
         console.writeline($"this is {this.gettype().name} {this.name} audit");
         if (context.hour <= 8)
         {
             context.auditresult = true;
             context.auditremark = "允许请假！";
         }
     }   
}


 public class charge
 {
     public override void audit(applycontext context)
     {
         console.writeline($"this is {this.gettype().name} {this.name} audit");
         if (context.hour <= 16)
         {
             context.auditresult = true;
             context.auditremark = "允许请假！";
         }
    }
}


 public class manager 
 {
     public override void audit(applycontext context)
     {
         console.writeline($"this is {this.gettype().name} {this.name} audit");
         if (context.hour <= 24)
         {
             context.auditresult = true;
             context.auditremark = "允许请假！";
         }
    }
}


 public class chief
 {
     public override void audit(applycontext context)
     {
         console.writeline($"this is {this.gettype().name} {this.name} audit");
         if (context.hour <= 48)
         {
             context.auditresult = true;
             context.auditremark = "允许请假！";
         }
    }
}



 public class ceo : abstractauditor
 {
     public override void audit(applycontext context)
     {
         console.writeline($"this is {this.gettype().name} {this.name} audit");
         if (context.hour <= 96)
         {
             context.auditresult = true;
             context.auditremark = "允许请假！";
         }
    }
}


public class chiarman : abstractauditor
{
    public override void audit(applycontext context)
    {
        console.writeline($"this is {this.gettype().name} {this.name} audit");
        if (context.hour <= 1000000)
        {
            context.auditresult = true;
            context.auditremark = "允许请假！";
        }
    }
}

下面进行逻辑的翻译：

 abstractauditor pm = new pm()
 {
     name = "bingle1"
 };
 pm.audit(context);
 if (!context.auditresult)
 {
     abstractauditor charge = new charge()
     {
         name = "bingle2"
     };
     charge.audit(context);
     if (!context.auditresult)
     {
         abstractauditor manager = new manager()
         {
             name = "bingle3"
         };
         manager.audit(context);
         if (!context.auditresult)
         {
             //找下一环节
         }
     }
 }

不要直接翻译的逻辑，需要涉及，现在的场景分析是，1、权限范围内，审批通过；2、权限范围外，交给下一环节审批，写的代码又多了一个，指定洗衣环节，甩锅大法开始。

首先定义一个抽象父类：

public abstract class abstractauditor
{
    public string name { get; set; }
    public abstract void audit(applycontext context);

    private abstractauditor _nextauditor = null;
    public void setnext(abstractauditor auditor)
    {
        this._nextauditor = auditor;
    }
    protected void auditnext(applycontext context)
    {
        if (this._nextauditor != null)
        {
            this._nextauditor.audit(context);
        }
        else
        {
            context.auditresult = false;
            context.auditremark = "不允许请假！";
        }
    }
}

领导类需要继承这个抽象类：

 public class pm : abstractauditor
 {
     public override void audit(applycontext context)
     {
         console.writeline($"this is {this.gettype().name} {this.name} audit");
         if (context.hour <= 8)
         {
             context.auditresult = true;
             context.auditremark = "允许请假！";
         }
         else
         {
             abstractauditor charge = new charge()
             {
                 name = "象扑君"
             };
             charge.audit(context);
         }
     }
 }

 

其他的领导类以此类推.....

调用的时候，只需要找最低权限的人，去审批

abstractauditor pm = new pm()
{
    name = "bingle"
};
pm.audit(context);

以上，转移了申请提交的逻辑，这次符合实际情况，有了自己的思考和设计在里面。

 

甩锅大法开始了，一样，领导类需要实现抽象父类，不过在audit方法中稍作了改动

 public class pm : abstractauditor
 {
     public override void audit(applycontext context)
     {
         console.writeline($"this is {this.gettype().name} {this.name} audit");
         if (context.hour <= 8)
         {
             context.auditresult = true;
             context.auditremark = "允许请假！";
         }
         else
         {
             base.auditnext(context);
         }
     }
 }



 public class manager : abstractauditor
 {
     public override void audit(applycontext context)
     {
         console.writeline($"this is {this.gettype().name} {this.name} audit");
         if (context.hour <= 24)
         {
             context.auditresult = true;
             context.auditremark = "允许请假！";
         }
         else
         {
             base.auditnext(context);
         }
     }
 }


public class chief : abstractauditor
{
    public override void audit(applycontext context)
    {
        console.writeline($"this is {this.gettype().name} {this.name} audit");
        if (context.hour <= 48)
        {
            context.auditresult = true;
            context.auditremark = "允许请假！";
        }
        else
        {
            base.auditnext(context);
        }
    }
}


public class chiarman : abstractauditor
{
    public override void audit(applycontext context)
    {
        console.writeline($"this is {this.gettype().name} {this.name} audit");
        if (context.hour <= 1000000)
        {
            context.auditresult = true;
            context.auditremark = "允许请假！";
        }
        else
        {
            base.auditnext(context);
        }
    }
}


 public class charge: abstractauditor
 {
     public override void audit(applycontext context)
     {
         console.writeline($"this is {this.gettype().name} {this.name} audit");
         if (context.hour <= 16)
         {
             context.auditresult = true;
             context.auditremark = "允许请假！";
         }
         else
         {
             base.auditnext(context);
         }
     }
 }

 public class ceo : abstractauditor
 {
     public override void audit(applycontext context)
     {
         console.writeline($"this is {this.gettype().name} {this.name} audit");
         if (context.hour <= 96)
         {
             context.auditresult = true;
             context.auditremark = "允许请假！";
         }
         else
         {
             base.auditnext(context);
         }
     }
 }

下面需要找领导审批了：

abstractauditor pm = new pm()
{
    name = "bingle1"
};
abstractauditor charge = new charge()
{
    name = "bingle1"
};
abstractauditor manager = new manager()
{
    name = "bingle1"
};
abstractauditor chief = new chief()
{
    name = "bingle1"
};
abstractauditor ceo = new ceo()
{
    name = "bingle1"
};

//pm.setnext(charge);
//charge.setnext(manager);
pm.setnext(manager);
manager.setnext(chief);
chief.setnext(ceo);
ceo.setnext(new chiarman()
{
    name = "bingle1"
});
//流程的可扩展

pm.audit(context);

 if (!context.auditresult)
 {
     console.writeline("不干了！");
 }

以上，把流畅环节逻辑从业务类转移了。