前言
由于下面的机房收费系统重构自己要用VB.NET进行重构,所以在敲三层登录的时候,实践了一份C#版三层登录,接着就是VB.NET版的三层登录。话说还有七层登录,一下子感觉三层又矮小了。万丈高楼平地起,都得从最底层走起~
VB.NET版三层登录
Entity实体层
<span style="font-family:KaiTi_GB2312;font-size:18px;">Public Class UserInfo '定义两个私有属性 Private UserID As String Private Password As String '定义属性过程,通过属性过程,允许其他类访问 Public Property ID As String Get Return UserID End Get Set(value As String) UserID = value End Set End Property Public Property PWD As String Get Return Password End Get Set(value As String) Password = value End Set End Property End Class</span>
U层
<span style="font-family:KaiTi_GB2312;font-size:18px;">Public Class Frmlogin Private Sub btnExit_Click(sender As Object,e As EventArgs) Handles btnExit.Click End End Sub Private Sub btnOK_Click(sender As Object,e As EventArgs) Handles btnOK.Click '实例化传实体对象; Dim LoginUser As New Login.Model.UserInfo '用来接收用户的登录名和密码; '实例化B层对象 Dim Bcheck As New Login.BLL.LoginManager '将文本框中的字符串送给实体对象login.user使实体对象能够带上参数; LoginUser.ID = txtUsername.Text() LoginUser.PWD = txtPassword.Text() If Bcheck.selectUIandModel(LoginUser) Then MsgBox("恭喜你,成功了!Amazing") Else MsgBox("这也太笨了吧,连这个都做不好,怎么谈是精英?") End If End Sub End Class</span>
B层
<span style="font-family:KaiTi_GB2312;font-size:18px;">Imports Login.Model Imports Login.DAL.UserDAO Public Class LoginManager 'B层业务处理逻辑:承接U层的参数和传递到D层; Function selectUIandModel(ByVal user As Login.Model.UserInfo) As Boolean Dim DAOuser As New Login.DAL.UserDAO '实例化D层的UserDAO类 Dim Moderuser As New Login.Model.UserInfo '实例化实体层UserInfo类 Moderuser.ID = user.ID Moderuser = DAOuser.selectUserInfoFormUserInfoTable(Moderuser) '引用了DAL层的方法 If Moderuser.PWD = user.PWD Then Return True Else Return False End If End Function End Class</span>
D层
<span style="font-family:KaiTi_GB2312;font-size:18px;">Imports System.Data.sqlClient Imports Login.Model Public Class UserDAO 'server是服务器的名称,可以是local,IP地址,计算机名称; 'database是数据库的名称; 'userid是登录的用户名; 'pwd是登录的密码; Dim sqlConnectStr As String = "server =ZLT;database=Login;uid=sa;pwd=123" '下面可以用windows身份验证登录; 'Dim sqlConnectStr1 As String = "server=ZLT;database=Login;integrated Security=true" Dim sqlConnect1 As sqlConnection = New sqlConnection(sqlConnectStr) Function selectUserInfoFormUserInfoTable(ByVal user As Login.Model.UserInfo) As Login.Model.UserInfo Dim sql As String = "select * from Users where Username='" & user.ID & "'" Dim cmd As sqlCommand = New sqlCommand(sql,sqlConnect1) '定义sqlcommand对象; Dim read As sqlDataReader '定义sqldatareader对象; Dim UserDataTable As New DataTable '定义一个Datatable对象; Dim user1 As New Login.Model.UserInfo Try sqlConnect1.open() read = cmd.ExecuteReader UserDataTable.Load(read) user1.ID = UserDataTable.Rows(0)("Username") user1.PWD = UserDataTable.Rows(0)("Password") Return user1 Catch ex As Exception user1.PWD = "" Return user1 Finally If Not Isnothing(sqlConnect1) Then sqlConnect1.Close() End If End Try End Function End Class</span>
小结
1、人总得学会长大,三层也需要不断的创新;
2、万变不离其宗,变是永远不变的。
感谢您的宝贵时间~~~
原文地址:https://www.jb51.cc/vb/257153.html
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。