. Net data center charging system instance-three-tier + Design Mode

I recently worked on a. net data center charging system, which is compared with a simple three-tier system. Now I will post it to share with you! Package diagram: The design mode (Abstract Factory) is applied, so that there is no need to have a relationship (application interface) between layer B and layer D, and the abstract factory + reflection + configuration file is applied, the relationship between the factory and the D layer disappears, so that the B layer and the factory only need to know the interface of the D layer, and the D layer is decoupled. The class diagram is omitted here! Timing Diagram: The following is the implementation code. Of course, the login function is implemented in a simple architecture, and some logic processing in the timing diagram has not been applied. U layer: [vb] Public Class Form Private Sub butExit_Click (ByVal sender As System. object, ByVal e As System. eventArgs) Handles butExit. click End Sub Private Sub butLogin_Click (ByVal sender As System. object, ByVal e As System. eventArgs) Handles butLogin. click' defines an object class object and assigns the content in the text box to the object class Object Dim user As Model. teacher = New Model. teacher user. user_ID = txt UserID. text. toString () user. user_PWD = txtUserPWD. text. toString () 'defines a business logic layer object, and notifies the user of the information Dim fd As Facade based on the results returned by the business logic layer. userF = New Facade. userF If fd. query (user) Then MsgBox (True) Else MsgBox (False) End If End Sub End Class Facede layer: [vb] Public Class UserF Dim uB As BLL. userBLL = New BLL. userBLL Function Query (ByVal user As Model. teacher) As Boolean If uB. queryUser (user) Then Return (True) Else Return (False) End If End Function End Class B layer [vb] Public Class UserBLL Dim factory As Factory. userFactory = New Factory. userFactory Dim IUserDAL As IDAL. IUserIDAL Public Function QueryUser (ByVal user As Model. teacher) As Boolean IUserDAL = factory. createUserDAL () If IUserDAL. query_user (user) Then Return (True) Else Return (False) End If End Function End Class Factory layer [vb] Imports System. reflection Imp Orts System. configuration Public Class UserFactory Public Function CreateUserDAL () As IDAL. IUserIDAL Dim AssemblyName = "DAL" 'dim create = "User" Dim create As String = ConfigurationManager. deleetask( "create") Dim className As String 'dim user As DAL. userDAL = New DAL. userDAL 'Return user className = AssemblyName + ". "+ create +" DAL "Return CType (Assembly. load (AssemblyName ). createInstance (FIG) SsName), IDAL. IUserIDAL) End Function End Class IDAL layer [vb] Imports Model Public Interface IUserIDAL Function Query_user (ByVal user As Teacher) As Boolean End Interface, we are also growing up with continuous stumbling lines. It is such a growth that allows us to gradually understand new things and learn about it so that we can grasp it!