frmsyslogon.frm

图书管理系统

VERSION 5.00
Begin VB.Form SystemLogon 
   BorderStyle     =   3  'Fixed Dialog
   Caption         =   "图书管理系统用户登录"
   ClientHeight    =   2550
   ClientLeft      =   45
   ClientTop       =   330
   ClientWidth     =   4680
   ControlBox      =   0   'False
   LinkTopic       =   "Form2"
   MaxButton       =   0   'False
   MinButton       =   0   'False
   ScaleHeight     =   2550
   ScaleWidth      =   4680
   ShowInTaskbar   =   0   'False
   Begin VB.CommandButton cmdCancel 
      Cancel          =   -1  'True
      Caption         =   "取消"
      Height          =   375
      Left            =   2640
      TabIndex        =   5
      Top             =   1800
      Width           =   1095
   End
   Begin VB.CommandButton cmdOk 
      Caption         =   "确定"
      Height          =   375
      Left            =   1200
      TabIndex        =   4
      Top             =   1800
      Width           =   975
   End
   Begin VB.TextBox txtLog 
      Height          =   375
      IMEMode         =   3  'DISABLE
      Index           =   1
      Left            =   1320
      MaxLength       =   6
      PasswordChar    =   "*"
      TabIndex        =   1
      Top             =   1080
      Width           =   2535
   End
   Begin VB.TextBox txtLog 
      Height          =   375
      Index           =   0
      Left            =   1320
      MaxLength       =   5
      TabIndex        =   0
      Top             =   480
      Width           =   2535
   End
   Begin VB.Label Label2 
      AutoSize        =   -1  'True
      Caption         =   "口令 "
      Height          =   180
      Left            =   840
      TabIndex        =   3
      Top             =   1200
      Width           =   450
   End
   Begin VB.Label Label1 
      AutoSize        =   -1  'True
      Caption         =   "编号"
      Height          =   180
      Left            =   840
      TabIndex        =   2
      Top             =   600
      Width           =   360
   End
End
Attribute VB_Name = "SystemLogon"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Const MaxLogTimes As Integer = 3    '定义允许用户验证登录信息的最大次数

Private Sub cmdCancel_Click()
    '请求用户确认是否真的退出系统登录
    If MsgBox("你选择了退出系统登录，退出将不能启动管理系统！" & vbCrLf _
              & "是否真的退出？", vbYesNo, "登录验证") = vbYes Then
        Unload Me               '卸载登录窗体
    End If
End Sub

Private Sub cmdOk_Click()
    '静态常量intLogTimes用于保存用户请求验证的次数
    Static intLogTimes As Integer
    intLogTimes = intLogTimes + 1     '保存登录次数
    If intLogTimes > MaxLogTimes Then
        '超过允许的登录次数，显示提示信息
        MsgBox "你已经超过允许的登录验证次数！" & vbCr _
               & "应用程序将结束！", vbCritical, "登录验证"
        End         '结束应用程序
    Else
        With Library_Manage.rsSysUsers      '检验用户编号和口令的合法性
            .Open
            If .RecordCount > 0 Then
                .MoveFirst
                .Find "编号='" & Trim(txtLog(0)) & "'"
                If .EOF Then
                    MsgBox Trim(txtLog(0)) & "不是系统用户，请检查输入！", _
                           vbCritical, "登录验证"
                    txtLog(0).SetFocus
                    txtLog(0).SelStart = 0
                    txtLog(0).SelLength = Len(txtLog(0))
                ElseIf .Fields("口令") <> Trim(txtLog(1)) Then
                    MsgBox "口令错误，请重新输入口令！", vbCritical, "登录验证"
                    txtLog(1).SetFocus
                    txtLog(1) = ""
                Else
                    CurrentUserNum = .Fields("编号")
                    CurrentUserPassword = .Fields("口令")
                    CurrentUserStatus = .Fields("权限")
                    MsgBox "欢迎使用北京交通大学管理系统！", vbInformation, "登录成功"
                    Unload Me
                    SystemMain.Show         '显示系统主窗体
                End If
            End If
            .Close     '关闭记录集
        End With
    End If
End Sub