form1.frm

学生信息管理系统.一个简单的学生信息管理系统,可以做些日常学生信息的管理.

VERSION 5.00
Begin VB.Form SysLogon 
   Caption         =   "学生信息管理系统"
   ClientHeight    =   2670
   ClientLeft      =   4650
   ClientTop       =   2925
   ClientWidth     =   4245
   ScaleHeight     =   2670
   ScaleWidth      =   4245
   StartUpPosition =   2  '屏幕中心
   Begin VB.CommandButton cmdCancel 
      Caption         =   "退出"
      Height          =   375
      Left            =   2520
      TabIndex        =   5
      Top             =   2040
      Width           =   1455
   End
   Begin VB.CommandButton cmdOK 
      Caption         =   "登陆"
      Default         =   -1  'True
      Height          =   375
      Left            =   480
      TabIndex        =   4
      Top             =   2040
      Width           =   1335
   End
   Begin VB.TextBox txtLog 
      Height          =   375
      IMEMode         =   3  'DISABLE
      Index           =   1
      Left            =   1440
      PasswordChar    =   "*"
      TabIndex        =   3
      Top             =   1200
      Width           =   2175
   End
   Begin VB.TextBox txtLog 
      Height          =   375
      Index           =   0
      Left            =   1440
      TabIndex        =   2
      Top             =   480
      Width           =   2175
   End
   Begin VB.Label Label2 
      Caption         =   "密  码："
      Height          =   255
      Left            =   720
      TabIndex        =   1
      Top             =   1320
      Width           =   855
   End
   Begin VB.Label Label1 
      Caption         =   "用户名："
      Height          =   255
      Left            =   720
      TabIndex        =   0
      Top             =   600
      Width           =   735
   End
End
Attribute VB_Name = "SysLogon"
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()
    intLogTimes = intLogTimes + 1     '保存登录次数,静态常量intLogTimes用于保存用户请求验证的次数
    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
        '检验用户名和口令的合法性，并根据检验返回值执行相应的操作
        Select Case Check_PassWord()
            Case 0
                '用户不是系统用户
                MsgBox TxtLog(0) & " 不是系统用户," _
                       & "请检查用户名输入是否正确！", _
                       vbCritical, "登录验证"
                TxtLog(0).SetFocus
                TxtLog(0).SelStart = 0
                TxtLog(0).SelLength = Len(TxtLog(0))
            Case 1
                '口令错误
                MsgBox "口令错误,请重新输入！", vbCritical, "登录验证"
                TxtLog(1) = ""
                TxtLog(1).SetFocus
            Case 2
                 '口令正确
                Unload Me           '卸载登录窗体
                MsgBox "登录成功，将启动系统管理程序！", _
                       vbInformation, "登录验证"
             SysMain.Show    '显示系统主窗体
             Connect_Database
            Case Else
                '登录验证未正常完成
                MsgBox "登录验证未正常完成！请重新运行登录程序，" _
                      & vbCrLf & "如果仍不能登录，请报告系统管理员！", _
                       vbCritical, "登录验证"
        End Select
    End If
End Sub

Private Function Check_PassWord() As Byte
  '  On Error GoTo gpError
    Connect_Database
    '执行查询命令,获得用户登录口令
    strSQL = "SELECT * FROM 系统用户 WHERE 用户名='" & TxtLog(0) & "'"
    Set objRs.ActiveConnection = objCn
    objRs.Open (strSQL), , adOpenKeyset, adLockOptimistic
    '判断有无查询结果
    If objRs.EOF Then
        Check_PassWord = 0      '没有查询结果，表示该用户为非法用户
    Else
        '检查口令是否正确
        If TxtLog(1) <> Trim(objRs.Fields("口令")) Then
            Check_PassWord = 1                      '口令不正确
        Else
            Check_PassWord = 2                      '口令正确
            '保存用户信息
            CurrentUserName = objRs.Fields("用户名").Value
            CurrentUserPassword = objRs.Fields("口令").Value
            CurrentUserStatus = objRs.Fields("身份").Value
            CurrentUserLogonTime = objRs.Fields("登陆次数").Value + 1
            LastUserLogonDate = objRs.Fields("登陆日期").Value
            LastUserLogonTime = objRs.Fields("登陆时间").Value
            objRs.Fields("登陆日期").Value = Date
            objRs.Fields("登陆时间").Value = Time()
            objRs.Fields("登陆次数").Value = objRs.Fields("登陆次数").Value + 1
            objRs.Update
        End If
    End If
    
    Close_Database '关闭数据库连接，释放对象
    
    Exit Function
'gpError:
 '   Check_PassWord = 255
End Function