机房收费系统登录功能的代码记录

      机房收费系统第三遍做的时候加入了工厂和接口，下面以登录为例记录了从UI层到Bll层（期间有工厂和接口）的代码。

UI层：

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''  frmLogin.vb
''  Implementation of the Class frmLogin
''  Generated by Enterprise Architect
''  Created on:    07-五月-2011 15:40:01
''  Original author: 黄爱岗
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''  Modification history:
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Option Explicit On
Option Strict On

''' <summary>
''' 登陆窗体
''' </summary>
Public Class frmLogin

    Dim BllFactory As New BllFactory.BllFactory     '定义Bll工厂产生Bll
    Dim WorkUser As New Entity.EntityOnWorkInfo     '定义正在工作用户实体类
    Dim UserInfo As New Entity.EntityUserInfo      '定义用户信息实体类

   ''' <summary>
    ''' 登陆
    ''' </summary>
    Private Sub btnLogin_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLogin.Click

        '判断文本框是否为空
        If Trim(TxtUserID.Text) = Trim("") Then
            MsgBox("用户名不能为空！", vbOKOnly, "警告")
            Exit Sub
        ElseIf Trim(TxtPwd.Text) = Trim("") Then
            MsgBox("密码不能为空！", vbOKOnly, "警告")
            Exit Sub
        End If

        '给用户信息实体类赋值
        UserInfo.UserID = Trim(TxtUserID.Text)
        UserInfo.UserPwd = Trim(TxtPwd.Text)

        '调用用户登陆方法，显示主窗体
        Try
            BllFactory.CreateILogin.LoginSystem(UserInfo)
            Me.Hide()    '隐藏登陆窗体
            Select Case UserInfo.UserLevel     '根据不同用户的不同级别显示不同的主窗体
                Case "一般用户"
                    frmMainStuOnOffLine.Show()    '显示一般用户的主窗体
                Case "操作员"
                    frmMainRegisterCard.Show()    '显示操作员的主窗体
                Case "管理员"
                    frmMainReckon.Show()          '显示管理员的主窗体
            End Select
        Catch ex As Exception
            MsgBox(ex.Message)      '显示抓住的消息
            Me.TxtPwd.Text = ""     '清空用户密码文本框
            Me.TxtUserID.Text = ""  '清空用户名文本框
        End Try

    End Sub

End Class

工厂BllFactory层：

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''  BllFactory.vb
''  Implementation of the Class BllFactory
''  Generated by Enterprise Architect
''  Created on:      04-五月-2011 15:39:48
''  Original author: asus
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''  Modification history:
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Option Explicit On
Option Strict On

Imports BllInterface
Imports System.Reflection

''' <summary>
''' 根据需要通过反射的方式建造不同的BLL类
''' </summary>
Public Class BllFactory

    Private Bll As String = System.Configuration.ConfigurationSettings.AppSettings("Bll1")

   ''' <summary>
    ''' 创建登陆接口
    ''' </summary>
    Public Function CreateILogin() As ILogin
        Return CType(Assembly.Load(Bll).CreateInstance(Bll & ".BllLogin"), ILogin)
    End Function
End Class

接口ILogin层：

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''  ILogin.vb
''  Implementation of the Interface ILogin
''  Generated by Enterprise Architect
''  Created on:      04-五月-2011 15:40:05
''  Original author: asus 
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''  Modification history:
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Option Explicit On
Option Strict On

Imports Entity

''' <summary>
''' 登陆的接口
''' </summary>
Public Interface ILogin

    ''' <summary>
    ''' 登陆系统，查询用户信息，判断密码、级别和用户使用状态，同时将登陆信息写入用户登陆临时表中
    ''' </summary>
    ''' <param name="entityUserInfo">用户信息</param>
    Sub LoginSystem(ByVal entityUserInfo As EntityUserInfo)

End Interface

BLL层：

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''  BllLogin.vb
''  Implementation of the Class BllLogin
''  Generated by Enterprise Architect
''  Created on:      07-五月-2011 15:39:49
''  Original author: 黄爱岗
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
''  Modification history:
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Option Explicit On
Option Strict On

Imports Entity
Imports BllInterface

''' <summary>
''' 登陆
''' </summary>
Public Class BllLogin
    Implements BllInterface.ILogin
    Dim DalFactory As New DalFactory.DalFactory    '定义Dal工厂产生Dal
    Public strComputerNum As String = System.Configuration.ConfigurationSettings.AppSettings("ComputerNum") '读取配置文件中机房号字段

   ''' <summary>
    ''' 登陆系统，查询用户信息，判断密码、级别和用户使用状态，同时将登陆信息写入用户登陆临时表中
    ''' </summary>
    ''' <param name="entityUserInfo">用户信息</param>
    Public Sub LoginSystem(ByVal entityUserInfo As EntityUserInfo) Implements ILogin.LoginSystem

        Dim UserInfo As New DataSet      '定义一个用户实体类用来接收从用户信息表传来的用户信息
        Dim OnWorkUser As New DataSet      '定义一个用户实体类用来接收从正在工作用户表传来的用户信息
        Dim entityWorkUser As New EntityOnWorkInfo   '定义正在工作用户实体类

        '根据用户ID获取用户信息
        UserInfo = DalFactory.CreateIUserInfo.QueryByID(entityUserInfo)
        '判断UserInfo是否为空，空则抛出消息
        If UserInfo Is Nothing Or UserInfo.Tables(0).Rows.Count = 0 Then
            Throw New Exception("用户不存在！")
        End If

        '给实体类的用户ID属性赋值
        entityWorkUser.UserID = Trim(entityUserInfo.UserID)
        '根据用户ID获取正在工作用户信息
        OnWorkUser = DalFactory.CreateIOnWorkInfo.QueryByID(entityWorkUser)
        '判断此用户是否已登录
        If OnWorkUser.Tables(0).Rows.Count > 0 Then
            Throw New Exception("此用户正在工作！")
        End If

        '判断用户状态是否可用，密码是否正确
        If UserInfo.Tables(0).Rows(0)("UseState").ToString() = Trim("False") Then
            Throw New Exception("此用户状态不可用！")
        ElseIf (Trim(UserInfo.Tables(0).Rows(0)("UserPwd").ToString()) = Trim(entityUserInfo.UserPwd)) = False Then
            Throw New Exception("卡号和密码不一致！")
        End If

        '给正在工作实体类的各字段赋值
        entityWorkUser.UserID = Trim(entityUserInfo.UserID)
        entityWorkUser.ComputerNo = Trim(strComputerNum)
        entityWorkUser.EnterDate = Date.Today
        entityWorkUser.EnterTime = TimeOfDay
        '添加用户信息到用户工作临时表中
        Try
            DalFactory.CreateIOnWorkInfo.AddOnWorkInfo(entityWorkUser)
            entityUserInfo.UserLevel = Trim(UserInfo.Tables(0).Rows(0)("UserLevel").ToString())  '给实体类赋值（用户级别）
        Catch ex As Exception
            Throw New Exception("登陆失败，请稍后重试！")
        End Try

    End Sub

End Class