login.frm

数据库要求：Access 2000或者更高的版本。 系统要求：Windows系列操作系统。 运行“安装程序”文件夹中的setup.exe文件

VERSION 5.00
Begin VB.Form frmLogin 
   BorderStyle     =   3  'Fixed Dialog
   Caption         =   "请登录"
   ClientHeight    =   1815
   ClientLeft      =   2835
   ClientTop       =   3480
   ClientWidth     =   4335
   LinkTopic       =   "Form1"
   LockControls    =   -1  'True
   MaxButton       =   0   'False
   MinButton       =   0   'False
   ScaleHeight     =   1072.362
   ScaleMode       =   0  'User
   ScaleWidth      =   4070.329
   ShowInTaskbar   =   0   'False
   StartUpPosition =   2  '屏幕中心
   Begin VB.CommandButton cmdOK 
      Caption         =   "确定"
      Default         =   -1  'True
      Height          =   390
      Left            =   3240
      TabIndex        =   8
      Top             =   240
      Width           =   900
   End
   Begin VB.CommandButton cmdCancel 
      Cancel          =   -1  'True
      Caption         =   "取消"
      Height          =   390
      Left            =   3240
      TabIndex        =   7
      Top             =   960
      Width           =   900
   End
   Begin VB.Frame frmLogin 
      Caption         =   "登录"
      Height          =   1695
      Left            =   120
      TabIndex        =   2
      Top             =   0
      Width           =   2895
      Begin VB.ComboBox cboUserType 
         Height          =   315
         ItemData        =   "Login.frx":0000
         Left            =   1080
         List            =   "Login.frx":000A
         Style           =   2  'Dropdown List
         TabIndex        =   3
         Top             =   1200
         Width           =   1485
      End
      Begin VB.TextBox txtPwd 
         Height          =   345
         IMEMode         =   3  'DISABLE
         Left            =   1080
         PasswordChar    =   "*"
         TabIndex        =   1
         Top             =   765
         Width           =   1485
      End
      Begin VB.TextBox txtUser 
         Height          =   345
         Left            =   1080
         TabIndex        =   0
         Top             =   360
         Width           =   1485
      End
      Begin VB.Label lblLabels 
         AutoSize        =   -1  'True
         Caption         =   "选择身份："
         Height          =   180
         Index           =   2
         Left            =   180
         TabIndex        =   6
         Top             =   1200
         Width           =   900
      End
      Begin VB.Label lblLabels 
         AutoSize        =   -1  'True
         Caption         =   "用户名："
         Height          =   195
         Index           =   0
         Left            =   360
         TabIndex        =   5
         Top             =   390
         Width           =   720
      End
      Begin VB.Label lblLabels 
         AutoSize        =   -1  'True
         Caption         =   "口令："
         Height          =   195
         Index           =   1
         Left            =   540
         TabIndex        =   4
         Top             =   795
         Width           =   540
      End
   End
End
Attribute VB_Name = "frmLogin"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit

'表示当前用户登录所选择的身份，即用户类型, 0-表示管理员；1-表示学生
Dim mnUserType As Integer

Private Sub cboUserType_Change()
    mnUserType = cboUserType.ListIndex
End Sub

Private Sub cboUserType_Click()
    mnUserType = cboUserType.ListIndex
End Sub

Private Sub cmdCancel_Click()
    Unload Me
End Sub

Private Sub cmdOK_Click()
    ''取得用户输入的用户名和密码
    Dim user As String, pwd As String
    user = txtUser
    pwd = txtPwd
        
    ''根据不同的身份，选择不同的表用以查询
    Dim r As New ADODB.Recordset
    Set r = DataEnv.rssqlSeek
    Dim strSQL As String
    Select Case mnUserType
        Case 0: '若身份为管理员
            strSQL = "select * from admin where name='" & user & "' and pwd='" & pwd & "'"
        Case 1: '若身份为学生
            strSQL = "select * from student where name='" & user & "' and serial='" & pwd & "'"
    End Select
    
    On Error Resume Next
    ''查询DataEnv.rssqlSeek的状态，如果已经打开，则先关闭
    If r.State = adStateOpen Then r.Close
    r.Open strSQL       ''根据strSQL的内容刷新DataEnv.rssqlSeek
       
    ''用户密码错误的次数，如果错误次数超过3次，则退出系统
    Static nTryCount As Integer
    
    If r.EOF Then   ''登录失败
      MsgBox "对不起，无此用户或者密码不正确！请重新输入！！", vbCritical, "错误"
      txtUser.SetFocus
      txtUser.SelStart = 0
      txtUser.SelLength = Len(txtUser)
      nTryCount = nTryCount + 1
      If nTryCount >= 3 Then
         MsgBox "您无权操作本系统!再见！", vbCritical, "无权限"
         Unload Me
      End If
    Else            ''登陆成功
      ''显示MDI窗体, 并将用户类型和用户名传到MDI窗体中的mnUserType, msUserName中
      Load MDIMain
      With MDIMain
        .mnUserType = cboUserType.ListIndex
        .msUserName = pwd
        .Show
      End With
      Unload Me
    End If
End Sub

Private Sub Form_Load()
    cboUserType.ListIndex = 0
End Sub