IDC reconstruction Abstract Factory + reflection + configuration file

It has been more than three weeks since the reconstruction of the data center. from the beginning to the end, we have no idea how to start.

Such as a reborn. Compared with two weeks ago, it is much clearer now, and the mood is quite good.

Let's take a look at the overall architecture diagram of this reconstruction:

In the previous blog, the three layers (ui, BLL, Dal, and entity) are hidden.

This blog focuses on the improvements I have made on the basis of Layer 3, that is, the legendary Layer 7.

1. facade layer (appearance layer)

Definition: provides a consistent interface for a group of interfaces in the subsystem. This mode defines a high-level interface, which makes the subsystem easier to use.

Personal Understanding: The appearance mode is like a directory, which integrates all the methods into this layer (like an interface) and is a node, what the U layer needs is called directly from the appearance layer, which reduces the coupling between the U layer and the B layer, facilitating the call of methods.

The data center reconstruction login form is used as an example to share the Code:

<Span style = "font-family: kaiti_gb2312; font-size: 18px; "> ''' <summary> ''' verify logon ''' </Summary> ''' <Param name =" enuser "> </param> ''' <returns> ture or false </returns> ''' <remarks> </remarks> Public Function select_faced (enuser as chargeentity. charget_usersentity) as Boolean dim selectfaced as new chargemanagerbll 'instantiate layer B dim dT as Boolean 'defines dT as set type dt = selectfaced. selectuserbll (enuser) 'calls the layer B function return DT end function </span>

2. Abstract Factory + reflection + configuration file-implement Database Access

Abstract Factory: provides an interface for creating a series of related or mutually dependent objects without specifying their specific classes.

Below is a method of my Abstract Factory

<Span style = "font-family: kaiti_gb2312; font-size: 18px;"> imports system. reflection 'introduce the reflection imports system. configuration 'reference Assembly imports chargeidal' reference interface public class charget_usersfactory private shared readonly assemblyname as string = "chargedal" 'declares the Assembly name private shared readonly dB as string = configurationmanager. appsettings ("DB ") ''' <summary> ''' User Logon ''' </Summary> ''' <returns> ture or false </returns> ''' <remarks> </ remarks> Public Function selectusers () as charget_usersidal dim iselect as chargeidal. charget_usersidal dim classname as string = "chargedal" + ". "+ dB +" charget_usersdal "'concatenates strings to achieve database access iselect = ctype (assembly. load (assemblyname ). createinstance (classname), charget_usersidal) return iselect end function </span>

Configuration File: App. config, which exists on the UI Layer.

<Span style = "font-family: kaiti_gb2312; font-size: 18px;"> 1. General Format: <configuration> 2 <configsections> // The Declaration area of the configuration section, contains the configuration section and namespace Declaration 3 <section> // configuration section declaration 4 <sectiongroup> // defines configuration section group 5 <section> // configuration section group configuration section declaration 6 <appsettings> // predefined configuration section 7 <custom element for configuration section> // configuration section setting area </span>

My configuration file:

<span style="font-family:KaiTi_GB2312;font-size:18px;">?xml version="1.0" encoding="utf-8" ?><configuration>    <startup>        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />    </startup>     <appSettings>          <add key="DB" value="Sqlserver"/>                  <add key ="sqlConnect" value ="Data source=.; Database =ChargeSystem; User ID = sa;Password = 123456 "/>      </appSettings>  </configuration></span>

Note: To write the configuration file, you must reference system. configuration. Note: When database is included in the concatenation string in the factory, change the class name corresponding to layer D.

Is: DB name + class name in the configuration file. Alternatively, you can remove the DB from the previous factory without changing the Class Name of the d layer.

 

Reflection: Provides encapsulated assembly, module, and type objects. I have used this in the abstract factory.

3. Interface: layer B calls the method of layer D through the interface and does not directly deal with the database. This reduces the coupling between layer B and layer D and ensures security.

Some of my interfaces:

<Span style = "font-family: kaiti_gb2312; font-size: 18px;"> mports chargeentity public interface charget_usersidal 'defines the login interface function selectusers (enuser as chargeentity. charget_usersentity) as List (of chargeentity. charget_usersentity) 'defines the function changepwd_dal (enuser as chargeentity. charget_usersentity) as Boolean 'defines the function adduser_dal (enuser as chargeentity. charget_usersentity) as integer 'defines the query user interface function finduser_dal (enuser as chargeentity. charget_usersentity) as List (of chargeentity. charget_usersentity) 'defines the function deleteuser_dal (enuser as chargeentity. charget_usersentity) as integer End Interface </span>

Personal eyes: The appearance layer and interface layer are actually the same, reducing the coupling of each layer and making the call method more convenient. Create a connection through an abstract factory

Interface. layer I defines the interface and layer D implements the interface. This is also called interface-oriented programming. Database Access is realized through abstract factory + reflection + configuration file

Q: It makes database replacement more flexible and convenient in the future. Layering is actually like building a house. After the skeleton is set up (layering), the rest is slowly

It's just a pile of bricks.

IDC reconstruction Abstract Factory + reflection + configuration file