三层注册+VB.net实现
最近几天设计模式放了放，看了一套关于三层的视频，关于三层架构在VS中怎么实现登录，自己做了一下，下面是注意事项，以及步骤和代码。
第一步：
搭建环境
创建窗体
搭建三层：
新建解决方案
模板层 数据访问层 业务逻辑层
在解决方案中新建三个类库：编译成为dll文件
建立模板层：
模板层的作用：与数据库表字段一一对应的cs文件。
建立数据访问层：
注意事项：1、实际做工程中尽量用存储过程。
2、可以使用构造参数的方式。
3、拼接字符串---不可取
代码实现：
首先建立模板层：
模板层的主要作用是建立与数据库表字段一一对应的cs文件。
新建类m_userInfo
<textarea cols="50" rows="15" name="code" class="vb">Public Class m_userInfo Private _userID As Integer Private _userName As String Private _userPwd As String Private _email As String Private _qq As String ''' <summary> ''' 用户ID ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> Public Property userID() As Integer Get Return _userID End Get Set(ByVal value As Integer) _userID = value End Set End Property ''' <summary> ''' 用户姓名 ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> Public Property userName() As String Get Return _userName End Get Set(ByVal value As String) _userName = value End Set End Property ''' <summary> ''' 用户密码 ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> Public Property userPwd() As String Get Return _userPwd End Get Set(ByVal value As String) _userPwd = value End Set End Property ''' <summary> ''' 用户Email ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> Public Property email() As String Get Return _email End Get Set(ByVal value As String) _email = value End Set End Property ''' <summary> ''' 腾讯QQ ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> Public Property qq() As String Get Return _qq End Get Set(ByVal value As String) _qq = value End Set End Property End Class</textarea>
数据访问层（DAL）
<textarea cols="50" rows="15" name="code" class="vb">Imports System.Data.SqlClient '注意引用 Public Class da_userInfo Private connStr As String = "server=127.0.0.1;database=dakui;uid = sa;pwd=123" ''' <summary> ''' 获得一个用户信息 ''' </summary> ''' <param name="userId">用户ID</param> ''' <returns>一个用户对象</returns> ''' <remarks>2010-12-13 20:50 By Zsk</remarks> Public Function GetObject(ByVal userId As Integer) As Model.m_userInfo Dim sql As String = "select userName,userPwd,from,email,qq userInfo where userId = @userId" Dim conn As SqlConnection = New SqlConnection(connStr) Dim cmd As SqlCommand = New SqlCommand(sql, conn) Dim sqlParam As New SqlParameter("@userId", SqlDbType.Int) sqlParam.Value = userId Dim sdr As SqlDataReader = Nothing Dim modelUserInfo As New Model.m_userInfo Try sdr = cmd.ExecuteReader() While sdr.Read modelUserInfo.userID = userId modelUserInfo.userName = sdr.GetString(0) modelUserInfo.userPwd = sdr.GetString(1) modelUserInfo.email = sdr.GetString(2) modelUserInfo.qq = sdr.GetString(3) End While Return modelUserInfo Catch ex As Exception Return Nothing Finally If Not IsNothing(sdr) Then sdr.Close() sdr = Nothing End If If Not IsNothing(conn) Then conn.Close() conn = Nothing End If If Not IsNothing(cmd) Then cmd.Dispose() cmd = Nothing End If End Try End Function ''' <summary> ''' 获得多有用户 ''' </summary> ''' <returns>所有用户的DataSet集合</returns> ''' <remarks>2010-12-13 20:45 By Zsk</remarks> Public Function SelectAll() As DataSet Dim sql As String = "select * from userInfo" Dim conn As SqlConnection = New SqlConnection(connStr) Dim cmd As SqlCommand = New SqlCommand(sql, conn) Dim dap As SqlDataAdapter = New SqlDataAdapter(cmd) Dim ds As New DataSet Try conn.Open() dap.Fill(ds) Return ds Catch ex As Exception Return Nothing Finally If Not IsNothing(conn) Then conn.Close() conn = Nothing End If If Not IsNothing(cmd) Then cmd.Dispose() cmd = Nothing End If End Try End Function ''' <summary> ''' 删除一条用户信息 ''' </summary> ''' <param name="modelUserInfo">一个用户对象</param> ''' <returns>是否删除成功</returns> ''' <remarks>2010-12-13 20:41 By Zsk</remarks> Public Function Del(ByVal modelUserInfo As Model.m_userInfo) As Boolean Dim sql As String = "delete from userInfo where userId = @userId" Dim conn As SqlConnection = New SqlConnection(connStr) '注意引用 Dim cmd As New SqlCommand(sql, conn) Dim sqlParam As New SqlParameter("@userId", SqlDbType.Int) sqlParam.Value = modelUserInfo.userID Try conn.Open() Return cmd.ExecuteNonQuery() > 0 Catch ex As Exception Return False Finally If Not IsNothing(conn) Then conn.Close() conn = Nothing End If If Not IsNothing(cmd) Then cmd.Dispose() cmd = Nothing End If End Try End Function ''' <summary> ''' 更新一条用户信息 ''' </summary> ''' <param name="modelUserInfo">一个用户对象</param> ''' <returns>更新是否成功</returns> ''' <remarks>2010-12-13 20:40 By Zsk</remarks> Public Function Update(ByVal modelUserInfo As Model.m_userInfo) As Boolean Dim sql As String = "update userInfo set userName = @userName,userPwd=@userPwd,email=@email,qq=@qq where userId=@userId" Dim conn As SqlConnection = New SqlConnection(connStr) Dim cmd As SqlCommand = New SqlCommand(sql, conn) Dim sqlParam As SqlParameter sqlParam = New SqlParameter("@userName", SqlDbType.VarChar) sqlParam.Value = modelUserInfo.userID cmd.Parameters.Add(sqlParam) sqlParam = New SqlParameter("@userPwd", SqlDbType.VarChar) sqlParam.Value = modelUserInfo.userPwd cmd.Parameters.Add(sqlParam) sqlParam = New SqlParameter("@email", SqlDbType.VarChar) sqlParam.Value = modelUserInfo.email cmd.Parameters.Add(sqlParam) sqlParam = New SqlParameter("@qq", SqlDbType.VarChar) sqlParam.Value = modelUserInfo.qq cmd.Parameters.Add(sqlParam) sqlParam = New SqlParameter("@userId", SqlDbType.Int) sqlParam.Value = modelUserInfo.userID cmd.Parameters.Add(sqlParam) Try conn.Open() Return cmd.ExecuteNonQuery() > 0 Catch ex As Exception Return False Finally If Not IsNothing(conn) Then conn.Close() conn = Nothing End If If Not IsNothing(cmd) Then cmd.Dispose() cmd = Nothing End If End Try End Function ''' <summary> ''' 插入一条注册信息 ''' </summary> ''' <param name="modelUserInfo">一个用户信息表的对象</param> ''' <returns>是否添加成功</returns> ''' <remarks>2010-12-13 20:40 By Zsk</remarks> Public Function Insert(ByVal modelUserInfo As Model.m_userInfo) As Boolean Dim sql As String = "insert into userInfo(userName,userPwd,email,qq) values(@userName,@userPwd,@email,@qq)" '不能用拼接字符串的方式 Dim conn As SqlConnection = New SqlConnection(connStr) Dim cmd As SqlCommand = New SqlCommand(sql, conn) Dim sqlParam As SqlParameter sqlParam = New SqlParameter("@userName", SqlDbType.VarChar) sqlParam.Value = modelUserInfo.userName cmd.Parameters.Add(sqlParam) 'sqlParam = New SqlParameter("@userID", SqlDbType.VarChar) 'sqlParam.Value = modelUserInfo.userID 'cmd.Parameters.Add(sqlParam) sqlParam = New SqlParameter("@userPwd", SqlDbType.VarChar) sqlParam.Value = modelUserInfo.userPwd cmd.Parameters.Add(sqlParam) sqlParam = New SqlParameter("@email", SqlDbType.VarChar) sqlParam.Value = modelUserInfo.email cmd.Parameters.Add(sqlParam) sqlParam = New SqlParameter("@qq", SqlDbType.VarChar) sqlParam.Value = modelUserInfo.qq cmd.Parameters.Add(sqlParam) Try conn.Open() Return cmd.ExecuteNonQuery() > 0 Catch ex As Exception Return False Finally If Not IsNothing(conn) Then conn.Close() conn = Nothing End If If Not IsNothing(cmd) Then cmd.Dispose() cmd = Nothing End If End Try End Function End Class</textarea>
业务逻辑层（BLL）
主要是实现数据访问层中的方法，开始感觉有些多余，但是维护程序的时候一般数据访问层是不修改的，改主要是改业务逻辑层。
<textarea cols="50" rows="15" name="code" class="vb">Public Class b_userInfo Private accessUserInfo As New AccessDB.da_userInfo ''' <summary> ''' 获得一个用户信息 ''' </summary> ''' <param name="userId">用户ID</param> ''' <returns>一个用户对象</returns> ''' <remarks>2010-12-13 21:00 By Zsk</remarks> Public Function GetObject(ByVal userId As Integer) As Model.m_userInfo Return accessUserInfo.GetObject(userId) End Function ''' <summary> ''' 获得多有用户 ''' </summary> ''' <returns>所有用户的DataSet集合</returns> ''' <remarks>2010-12-13 21:05 By Zsk</remarks> Public Function SelectAll() As DataSet Return accessUserInfo.SelectAll() End Function ''' <summary> ''' 删除一条用户信息 ''' </summary> ''' <param name="modelUserInfo">一个用户对象</param> ''' <returns>是否删除成功</returns> ''' <remarks>2010-12-13 21:10 By Zsk</remarks> Public Function Del(ByVal modelUserInfo As Model.m_userInfo) As Boolean Return accessUserInfo.Update(modelUserInfo) End Function ''' <summary> ''' 插入一条注册信息 ''' </summary> ''' <param name="modelUserInfo">一个用户信息表的对象</param> ''' <returns>是否添加成功</returns> ''' <remarks>2010-12-13 21:15 By Zsk</remarks> Public Function Insert(ByVal modelUserInfo As Model.m_userInfo) As Boolean Return accessUserInfo.Insert(modelUserInfo) End Function ''' <summary> ''' 更新一条用户信息 ''' </summary> ''' <param name="modelUserInfo">一个用户对象</param> ''' <returns>更新是否成功</returns> ''' <remarks>2010-12-13 21:20 By Zsk</remarks> Public Function Update(ByVal modelUserInfo As Model.m_userInfo) As Boolean Return accessUserInfo.Update(modelUserInfo) End Function End Class </textarea>
窗体内代码
<textarea cols="50" rows="15" name="code" class="vb">Public Class frmExplame Private Sub btnSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSubmit.Click Dim modelUserInfo As New Model.m_userInfo Dim bllUserInfo As New BLL.b_userInfo modelUserInfo.userName = Me.txtUserName.Text modelUserInfo.userPwd = Me.txtUserPwd.Text modelUserInfo.email = Me.txtEmail.Text modelUserInfo.qq = Me.txtQQ.Text If bllUserInfo.Insert(modelUserInfo) Then labelMsg.Text = "添加成功" Else labelMsg.Text = "添加失败" End If End Sub End Class </textarea>