机房重构---下机（策略模式和职责连模式）

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前言：

下机需要查看消费时间以及选择用户类型，因此这里用到了职责连模式以及策略模式两种模式。消费时间用的是职责连模式，选择用户类型（固定用户，临时用户）。涉及多个表的查询，用视图是个不错的选择。

内容：

一、各个层调用关系：

二、UI层代码：

 Private Sub btnOffLine_Click(sender As Object, e As EventArgs) Handles btnOffLine.Click'1、卡号是否存在 2、卡号是否上机，上机记录表 '3、计算消费金额:1、小于（ 最少上机时间和准备时间）2、大于（ 最少上机时间和准备时间）小于递增时间 （临时和固定）'4、更新上机记录表，卡表If txtCardNo.Text = "" ThenMsgBox("请输入卡号")ReturnEnd IfDim table1 As New DataTableDim Card As New Entity.EntityCardDim line As New Entity.LineLogEntityDim facade As New Facade.OffLineFacadeDim table2 As New DataTableDim basic As New Entity.EntityBasicDataSetCard.CardNo = txtCardNo.Text()'查询卡表获取卡类型等table1 = facade.selectOffF(Card)'查询基础数据表table2 = facade.selectBasicF(basic)Card.type = table1.Rows(0).Item(3)Card.Balance = table1.Rows(0).Item(2)line.OnDate = table1.Rows(0).Item(1)line.OffDate = Format(Now, "yyyy-MM-dd HH:mm:ss")basic.LeastTime = table2.Rows(0).Item(5)basic.UnitTime = table2.Rows(0).Item(4)basic.ReadyTime = table2.Rows(0).Item(6)basic.tmpRate = table2.Rows(0).Item(3)basic.Rate = table2.Rows(0).Item(2)Dim facade2 As New Facade.CashContext'计算消费时间line.mins = facade.ConsumeTimeF(basic, Card, line)'选择卡类型line.Cash = facade2.SelectType(basic, Card, line)Card.Balance = CDec(Card.Balance) - CDec(line.Cash)line.CardNo = Card.CardNoDim flag As Booleanflag = facade.offLine(line, Card)If flag = True ThenMsgBox("下机成功")txtCardNo.Text = line.CardNotxtBalance.Text = Card.BalancetxtType.Text = Card.typetxtStudentNo.Text = table1.Rows(0).Item(5)txtStudentName.Text = table1.Rows(0).Item(6)txtDepartment.Text = table1.Rows(0).Item(8)txtSex.Text = table1.Rows(0).Item(7)txtOnDate.Text = line.OnDatetxtOffDate.Text = line.OffDatetxtmins.Text = line.minstxtCash.Text = line.CashElseMsgBox("下机失败")End IfEnd Sub

三、外观层

1、职责连查看消费时间

    Public Function ConsumeTimeF(ByVal basic As Entity.EntityBasicDataSet, ByVal card As Entity.EntityCard, ByVal line As Entity.LineLogEntity) As IntegerDim preparetime As New BLL.PrepareTimeBLL(basic)Dim leasttime As New BLL.LeastTimeBLL(basic)Dim unittime As New BLL.UintTimeBLLpreparetime.setsuccessor(leasttime)leasttime.setsuccessor(unittime)Dim time As Integertime = DateDiff("n", line.OnDate, line.OffDate)Return preparetime.TimeRequest(time)End Function

2、策略模式选择卡类型

Public Class CashContextDim cashsuper As CashSuper'根据策略 不同，采用不同的计费方式Public Function SelectType(ByVal basic As Entity.EntityBasicDataSet, ByVal card As Entity.EntityCard, ByVal line As Entity.LineLogEntity) As SingleSelect Case card.type.Trim()Case "固定用户"cashsuper = New FixedUserBLL() '实例化固定用户策略Case "临时用户"cashsuper = New TmpUserBLL()End SelectReturn cashsuper.GetConsumMoney(basic, card, line)End Function

四、BLL层

1、职责连查看消费时间

（1）时间基类

Public MustInherit Class TimeBLLProperty successor As TimeBLLPublic Sub setsuccessor(ByVal successor As TimeBLL) '设置继承类Me.successor = successorEnd Sub'请求处理的抽象方法Public MustOverride Function TimeRequest(ByVal time As Integer) As IntegerEnd Class

（2）LeastTimeBLL类

Public Class LeastTimeBLL : Inherits TimeBLLProtected leastTime As IntegerPublic Sub New(ByVal basic As Entity.EntityBasicDataSet)Me.leastTime = CInt(basic.LeastTime) '将至少上机时间赋值为leastTimeEnd SubPublic Overrides Function TimeRequest(time As Integer) As IntegerIf time <= leastTime Then '如果上机时间小于至少上机时间，返回至少上机时间  Return leastTimeElseReturn successor.TimeRequest(time)End IfEnd Function
End Class

（3）PreparetimeBLL类 

Public Class PrepareTimeBLL : Inherits TimeBLLDim preparetime As Integer' Public Sub New是VB.net默认的构造函数  form_load是Form类在调用New构造函数后加载窗体绘图后才调用的方法 Public Sub New(ByVal basic As Entity.EntityBasicDataSet)Me.preparetime = CInt(basic.ReadyTime)  '传入准备时间End SubPublic Overrides Function TimeRequest(time As Integer) As IntegerIf time <= preparetime Then '如果上机时间小于准备时间，返回0Return 0ElseReturn successor.TimeRequest(time)End IfEnd Function
End Class

（4）Unittime类

Public Class UintTimeBLL : Inherits TimeBLL'正常消费Public Overrides Function TimeRequest(time As Integer) As IntegerReturn timeEnd Function
End Class

2、策略模式选择卡类型：

（1）固定用户

Public Class FixedUserBLL : Inherits CashSuper'固定用户Dim fixedRate As SinglePublic Overrides Function GetConsumMoney(ByVal basic As Entity.EntityBasicDataSet, ByVal card As Entity.EntityCard, ByVal line As Entity.LineLogEntity) As SinglefixedRate = Trim(Int(basic.Rate))Dim consumMoney As SingleconsumMoney = Trim(CSng(fixedRate) * CSng(line.mins * 1.0 / 60.0))If consumMoney < Trim(Int(basic.Rate)) ThenconsumMoney = Int(basic.Rate)End IfReturn consumMoneyEnd Function
End Class

（2）临时用户

Public Class TmpUserBLL : Inherits CashSuper  '临时用户Dim TmpRate As SinglePublic Overrides Function GetConsumMoney(basic As Entity.EntityBasicDataSet, card As Entity.EntityCard, line As Entity.LineLogEntity) As SingleTmpRate = basic.tmpRateDim consumMoney As SingleconsumMoney = Trim(CSng(TmpRate) * CSng(line.mins * 1.0 / 60.0))If consumMoney < Int(basic.tmpRate) ThenconsumMoney = Int(basic.tmpRate)End IfReturn consumMoneyEnd Function
End Class

五、DAL层

Public Class AdcountDAL : Implements IDAL.IAdcountPublic Function update(adcount As EntityAdCount) As Integer Implements IAdcount.updateDim sql As StringDim sqlhelper As New SQLHelper.sqlhelperDim flag As IntegerDim paras As SqlParameter() = {New SqlParameter("@UserID", adcount.UserID),New SqlParameter("@CancelCash", adcount.CancelCash),New SqlParameter("@CheckCash", adcount.CheckCash),New SqlParameter("@RechCash", adcount.RechCash),New SqlParameter("@Checkdate", adcount.Checkdate)}sql = "proc_Account"flag = sqlhelper.ExecAddDelUpdate(sql, CommandType.StoredProcedure, paras)Return flagEnd Function
End Class

存储过程：

ALTER PROCEDURE [dbo].[pro_Offline]@CardNO varchar(20),@OffDate datetime,@mins    int,@Cash    numeric(10, 2),@state  varchar(20),@Balance numeric(10, 2)
AS
BEGINupdate Y_LineLog_Info set OffDate=@OffDate  ,mins =@mins  ,Cash=@Cash ,state=@state where CardNo =@CardNO  update Y_Card_Info set Balance=Balance  where CardNo =@CardNO  END

总结：

下机用到了两个设计模式，其实设计到哪部分特别复杂就该考虑用设计模式去解耦合，设计模式还需要我们继续去研究。

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