vb.net登录面代码 vb的登录界面如何制作

求一份VB.NET的注册页面的代码

创建完相应的用户名，密码控件之后，输入以下代码：

Imports System.Data.OleDb

Public Class Form1

Private Sub cmdok_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdok.Click

Dim m_username As String

Dim m_userpwd As String

Dim cmd_result As MsgBoxResult

Dim m_da As New OleDbDataAdapter

Dim m_ds As New DataSet

Dim m_command As New OleDbCommand

Dim strsql As String

m_username = txtusername.Text

m_userpwd = txtuserpwd.Text

strsql = " select * from user_info where username='" m_username "' and userpwd='" m_userpwd "'"

OleDbConnection1.Open()

m_command.CommandType = CommandType.Text

m_command.CommandText = strsql

m_command.Connection = OleDbConnection1

m_da.SelectCommand = m_command

m_da.Fill(m_ds, "user_info")

If m_ds.Tables("user_info").Rows.Count 0 Then

cmd_result = MsgBox("欢迎登录", MsgBoxStyle.OKOnly, "提示")

Else

MsgBox("登录失败，请确认用户名和密码")

End If

End Sub

End Class

用vb.net ，后台用access 做一个登录窗口

建个模块vb.net登录面代码， Dim varcnn As OleDb.OleDbConnection ReadOnly Property cnn() As OleDb.OleDbConnection

Get

If varcnn Is Nothing OrElse varcnn.State ConnectionState.Open Then Dim cnstr As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=""" My.Application.Info.DirectoryPath "\Contact.mdb"";Persist Security Info=True"

varcnn = New OleDbConnection(cnstr)

varcnn.Open()

End If

Return varcnn

End Get

登录窗体vb.net登录面代码，新建一个就行vb.net登录面代码了。代码Public Class LoginForm1

Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OK.Click

Using cmd As New OleDb.OleDbCommand("select password from tbuser where userid =?", cnn)

cmd.Parameters.Add("?", OleDbType.VarChar).Value = Me.UsernameTextBox.Text

Dim obj As Object = cmd.ExecuteScalar

If (Not IsDBNull(obj)) AndAlso (obj IsNot Nothing) AndAlso obj = PasswordTextBox.Text Then

Me.DialogResult = Windows.Forms.DialogResult.OK

Else MessageBox.Show("密码不正确vb.net登录面代码！") Return

End If

End Using Me.Close()

End Sub Private Sub Cancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Cancel.Click

Me.DialogResult = Windows.Forms.DialogResult.Cancel

Me.Close()

End SubEnd Class 项目属性里点查看应用程序事件，写代码Namespace My ' 以下事件可用于 MyApplication:

'

' Startup: 应用程序启动时在创建启动窗体之前引发。

' Shutdown: 在关闭所有应用程序窗体后引发。如果应用程序异常终止，则不会引发此事件。

' UnhandledException: 在应用程序遇到未处理的异常时引发。

' StartupNextInstance: 在启动单实例应用程序且应用程序已处于活动状态时引发。

' NetworkAvailabilityChanged: 在连接或断开网络连接时引发。

Partial Friend Class MyApplication

Private Sub MyApplication_Startup(ByVal sender As Object, ByVal e As Microsoft.VisualBasic.ApplicationServices.StartupEventArgs) Handles Me.Startup

Dim f As New LoginForm1

If Not f.ShowDialog = DialogResult.OK Then

End

End If

End Sub End ClassEnd Namespace

vb.net登录面代码你测试一下吧。

vb.net 连接SQL数据库登录代码

问题应该出在你的查询语句的结果没有值,你用你的查询语句到SQL中是否有返回值?记得加上你的条件,另外,你语句里这一句是多余的.Dim s As Object = sComm.ExecuteScalar 以下语句测试正常 Dim myCn As New SqlClient.SqlConnection Try myCn.ConnectionString = sConnString myCn.Open() Dim mySQL As String = "SELECT * FROM ygzl" Dim sComm As New SqlClient.SqlCommand(mySQL, myCn) If sComm.ExecuteScalar Then Dim User_MainForm As New Form1 User_MainForm.Show() Else MsgBox("用户名或密码不正确，请重试！") End If Catch ex As Exception MsgBox(ex.Message) Finally myCn.Close() '关闭连接 End Try

关于vb.net登录面代码和vb的登录界面如何制作的介绍到此就结束了，不知道你从中找到你需要的信息了吗 ？如果你还想了解更多这方面的信息，记得收藏关注本站。