login.frm

用VB编写的一个图书管理系统

VERSION 5.00
Begin VB.Form login 
   BackColor       =   &H00FFC0C0&
   Caption         =   "登录"
   ClientHeight    =   3150
   ClientLeft      =   60
   ClientTop       =   450
   ClientWidth     =   4365
   LinkTopic       =   "Form2"
   Picture         =   "login.frx":0000
   ScaleHeight     =   3150
   ScaleWidth      =   4365
   StartUpPosition =   2  '屏幕中心
   Begin VB.CommandButton Command2 
      Caption         =   "取消"
      Height          =   495
      Left            =   2400
      TabIndex        =   5
      Top             =   2040
      Width           =   1095
   End
   Begin VB.CommandButton Command1 
      Caption         =   "确定"
      Height          =   495
      Left            =   720
      TabIndex        =   4
      Top             =   2040
      Width           =   1095
   End
   Begin VB.TextBox txtpwd 
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   12
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   375
      IMEMode         =   3  'DISABLE
      Left            =   1680
      PasswordChar    =   "*"
      TabIndex        =   3
      Top             =   1080
      Width           =   1815
   End
   Begin VB.TextBox txtuser 
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   12
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   375
      Left            =   1680
      TabIndex        =   2
      Top             =   360
      Width           =   1815
   End
   Begin VB.Label Label2 
      Alignment       =   2  'Center
      AutoSize        =   -1  'True
      BackColor       =   &H8000000C&
      BackStyle       =   0  'Transparent
      Caption         =   "密  码："
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   10.5
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   330
      Left            =   600
      TabIndex        =   1
      Top             =   1080
      Width           =   960
   End
   Begin VB.Label Label1 
      Alignment       =   1  'Right Justify
      AutoSize        =   -1  'True
      BackColor       =   &H8000000C&
      BackStyle       =   0  'Transparent
      Caption         =   "用户名："
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   10.5
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   330
      Left            =   600
      TabIndex        =   0
      Top             =   480
      Width           =   960
   End
End
Attribute VB_Name = "login"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit
Dim cnt As Integer                     '记录确定次数

Private Sub Command1_Click()
Dim sql As String
Dim rs_login As New ADODB.Recordset
If Trim(txtuser.Text) = "" Then            '判断输入的用户名是否为空
   MsgBox "没有这个用户", vbOKOnly + vbExclamation, ""
   txtuser.SetFocus
Else
   sql = "select * from 系统管理 where 用户名='" & txtuser.Text & "'"
   rs_login.Open sql, conn, adOpenKeyset, adLockPessimistic
   If rs_login.EOF = True Then
      MsgBox "没有这个用户", vbOKOnly + vbExclamation, ""
      txtuser.SetFocus
   Else                                  '检验密码是否正确
      If Trim(rs_login.Fields(1)) = Trim(txtpwd.Text) Then
          userID = txtuser.Text
          userpow = rs_login.Fields(2)
          rs_login.Close
          Unload Me
          frmMain.Show
      Else
         MsgBox "密码不正确", vbOKOnly + vbExclamation, ""
         txtpwd.SetFocus
      End If
   End If
End If
cnt = cnt + 1
If cnt = 3 Then
   Unload Me
End If
Exit Sub
End Sub

Private Sub Command2_Click()
Unload Me
End Sub

Private Sub Form_Load()
Dim connectionstring As String
connectionstring = "provider=Microsoft.Jet.oledb.4.0;" & _
                   "data source=book.mdb"
conn.Open connectionstring
cnt = 0
End Sub