VB程序设计登陆界面代码详例

VB程序设计登陆界面代码详例 Imports System.Data.SqlClient Public Class frmMagementMain 'Inherits System.Windows.Forms.Form Dim constr As String = "User ID=sa;pwd=a;Initial Catalog=zbb;Data Source=(local)" '定义一个变量，连接字符串 Dim sqlstr As String = "select * from manid" '定义一个变量，SQL语句 Dim mycon As New SqlConnection(constr) '定义一个变量，为一个连接对象 Dim mycom As New SqlCommand(sqlstr, mycon) '定义一个变量，为命令对象 Dim myReader As SqlDataReader '定义一个变量，阅读器 Dim i As Integer = 0 Dim userIDsys() As Array Private Sub frmMagementMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load mycon.Open() '打开这个联接 myReader = mycom.ExecuteReader '把这个命令的连接送入阅读器 myReader.Read() Dim k As Integer = 0 While myReader.Read 'while 为遍历集合的每一项，用阅读器的read的方法来读取'定义一个变量的第一项 k = k + 1 'MsgBox(myReader.Item(1)) End While MsgBox(k) End Sub Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click ' Visual Basic 2005 ' Declare a new TextBox. Dim TextBox2 As New TextBox ' Set the location below the first TextBox TextBox2.Left = 102 TextBox2.Top = 242 ' Add the TextBox to the form's Controls collection. Me.Controls.Add(TextBox2) TextBox2.Text = "这可是我动态加的控件呀" End Sub Private Sub mnu_magement_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnu_magement.Click Dim frmlogin As frmlogin = New frmlogin frmlogin.Show() 'GBmagemetPeple.Left = 8 'GBmagemetPeple.Top = 28 'GBmagemetPeple.Visible = True End Sub Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click End Sub End Class ///////////////////////////////////// Imports System.Data.SqlClient Public Class frmlogin Dim i As Integer = 0 Dim constr1 As String = "" '定义一个变量，连接字符串 Dim sqlstr1 As String = "" Dim mycon1 As New SqlConnection(constr1) '定义一个变量，为一个连接对象 Dim mycom1 As New SqlCommand(sqlstr1, mycon1) '定义一个变量，为命令对象 Dim myReader1 As SqlDataReader '定义一个变量，阅读器 Private Sub OK_Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OK_Button.Click If txtUsename.Text = "" Or txtPassword.Text = "" Then MsgBox("请输入用户名和密码") Exit Sub End If sqlstr1 = "select * from mgpep where usernameID='" & txtUsename.Text & "' and passwordID='" & txtPassword.Text & "'" '定义一个变量，SQL语句 constr1 = "User ID=sa;pwd=a;Initial Catalog=SaleCD;Data Source=(local)" '定义一个 变量，连接字符串 mycon1.ConnectionString = constr1 mycom1.CommandText = sqlstr1 mycon1.Open() '重新打开这个联接 myReader1 = mycom1.ExecuteReader '第二次把这个命令的连接送入阅读器 If myReader1.VisibleFieldCount = 0 Then MsgBox("密码不对请重新输入～") Exit Sub End If myReader1.Read() '阅读器重新使用read方法 On Error GoTo ss If myReader1(0) > 0 Then frmMagementMain.GBmagemetPeple.Visible = True sqlstr1 = "select * from mgpep" If mycon1.State = 1 Then mycon1.Close() End If mycon1.Open() myReader1 = mycom1.ExecuteReader '把这个命令的连接送入阅读器 Dim userIDsys(myReader1.VisibleFieldCount - 1, 2) 'ReDim userIDsys(10, 2) Dim k As Integer = 0 While myReader1.Read frmMagementMain.CmbUser.Items.Add(myReader1(0)) For i = 0 To 2 userIDsys(k, i) = myReader1.Item(i) Next k = k + 1 End While MsgBox("已经成功登录～") mycon1.Close() Me.Close() Exit Sub Else MsgBox("您没有权限登录～") mycon1.Close() Me.Close() Exit Sub End If ss: MsgBox("您没有权限登录～") Me.Close() End Sub Private Sub Cancel_Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Cancel_Button.Click Me.Close() End Sub End Class