frmlogin.frm

很好的学习资料

VERSION 5.00
Begin VB.Form frmLogin 
   BorderStyle     =   3  'Fixed Dialog
   Caption         =   "登录"
   ClientHeight    =   1545
   ClientLeft      =   2835
   ClientTop       =   3480
   ClientWidth     =   3750
   LinkTopic       =   "Form1"
   MaxButton       =   0   'False
   MinButton       =   0   'False
   ScaleHeight     =   912.837
   ScaleMode       =   0  'User
   ScaleWidth      =   3521.047
   ShowInTaskbar   =   0   'False
   StartUpPosition =   2  '屏幕中心
   Begin VB.TextBox txtUserName 
      Height          =   345
      Left            =   1290
      TabIndex        =   1
      Top             =   135
      Width           =   2325
   End
   Begin VB.CommandButton cmdOK 
      Caption         =   "确定"
      Default         =   -1  'True
      Height          =   390
      Left            =   495
      TabIndex        =   4
      Top             =   1020
      Width           =   1140
   End
   Begin VB.CommandButton cmdCancel 
      Cancel          =   -1  'True
      Caption         =   "取消"
      Height          =   390
      Left            =   2100
      TabIndex        =   5
      Top             =   1020
      Width           =   1140
   End
   Begin VB.TextBox txtPassword 
      Height          =   345
      IMEMode         =   3  'DISABLE
      Left            =   1290
      PasswordChar    =   "*"
      TabIndex        =   3
      Top             =   525
      Width           =   2325
   End
   Begin VB.Label lblLabels 
      Caption         =   "用户名称(&U):"
      Height          =   270
      Index           =   0
      Left            =   105
      TabIndex        =   0
      Top             =   150
      Width           =   1080
   End
   Begin VB.Label lblLabels 
      Caption         =   "密码(&P):"
      Height          =   270
      Index           =   1
      Left            =   105
      TabIndex        =   2
      Top             =   540
      Width           =   1080
   End
End
Attribute VB_Name = "frmLogin"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
    Option Explicit
    Dim LoginSucceeded As Boolean
    
    Private Sub cmdCancel_Click()
        Unload frmLogin  '退出登陆对话框
        introfrm.Show    '显示初始窗体
    End Sub

    Private Sub cmdOK_Click()
    
    '检查用户身份
    If txtUserName.Text = "Administrator" Then
        LoginSucceeded = verify(txtUserName, txtPassword) '验证用户身份
        If (LoginSucceeded = True) Then
            ID = txtUserName
            admin = True     '标记管理用户为管理员，以赋予相应权限
            Unload frmLogin  '退出登陆对话框
            MDIMainfrm.Show  '显示程序主窗体界面
        End If
    Else
        LoginSucceeded = verify(txtUserName, txtPassword) '验证用户身份
        If (LoginSucceeded = True) Then
            ID = txtUserName
            admin = False    '标记为一般用户，以赋予相应权限
            Unload frmLogin  '退出登陆对话框
            MDIMainfrm.Show  '显示程序主窗体界面
        End If
    End If
    End Sub

    Function verify(userID As String, txtPWD As String) As Boolean
        Dim idinfo As Recordset
        Dim sqlstr As String
        
        sqlstr = "select 学号,密码 from 密码 where 学号='" & userID & "'"
        Set idinfo = courseDB.OpenRecordset(sqlstr, dbOpenSnapshot, dbReadOnly)
        '  到数据库中提取用户名和密码的记录
        If (idinfo.RecordCount = 0) Then  ' 无此用户时
            MsgBox "无此学号", , "登录"
            verify = False
        Else
            If (idinfo.Fields("密码").Value = txtPWD) Then
                verify = True  '登陆成功
            Else
                MsgBox "无效的密码，请重试!", , "登录"
                verify = False
            End If
        End If
        idinfo.Close
    End Function