login.frm

这个是一个图书管理系统

VERSION 5.00
Begin VB.Form login 
   Caption         =   "登录"
   ClientHeight    =   4230
   ClientLeft      =   60
   ClientTop       =   450
   ClientWidth     =   5835
   LinkTopic       =   "Form11"
   MaxButton       =   0   'False
   ScaleHeight     =   4230
   ScaleWidth      =   5835
   StartUpPosition =   2  '屏幕中心
   Begin VB.CommandButton Command2 
      Caption         =   "取消"
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   10.5
         Charset         =   134
         Weight          =   700
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   495
      Left            =   2400
      TabIndex        =   5
      Top             =   2280
      Width           =   1335
   End
   Begin VB.CommandButton Command1 
      Caption         =   "确定"
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   10.5
         Charset         =   134
         Weight          =   700
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   495
      Left            =   600
      TabIndex        =   4
      Top             =   2280
      Width           =   1335
   End
   Begin VB.TextBox Text2 
      Height          =   375
      IMEMode         =   3  'DISABLE
      Left            =   1200
      PasswordChar    =   "*"
      TabIndex        =   3
      Top             =   1200
      Width           =   1575
   End
   Begin VB.TextBox Text1 
      Height          =   375
      Left            =   1200
      TabIndex        =   2
      Top             =   480
      Width           =   1575
   End
   Begin VB.Label Label2 
      AutoSize        =   -1  'True
      Caption         =   "密码"
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   10.5
         Charset         =   134
         Weight          =   700
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   210
      Left            =   480
      TabIndex        =   1
      Top             =   1200
      Width           =   450
   End
   Begin VB.Label Label1 
      AutoSize        =   -1  'True
      Caption         =   "用户名"
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   10.5
         Charset         =   134
         Weight          =   700
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   210
      Left            =   480
      TabIndex        =   0
      Top             =   480
      Width           =   675
   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
Private Sub Command1_Click()
Dim sql As String
Dim rs_login As New ADODB.Recordset
If Trim(Text1.Text) = "" Then
MsgBox "没有这个用户", vbOKOnly + vbExclamation, ""
Text1.SetFocus
Else
sql = "select * from 系统管理 where 用户名='" & Text1.Text & "'"
rs_login.Open sql, conn, adOpenKeyset, adLockPessimistic
If rs_login.EOF = True Then
MsgBox "没有这个用户", vbOKOnly + vbExclamation, ""
Text1.SetFocus
Else
If Trim(rs_login.Fields(1)) = Trim(Text2.Text) Then
userID = Text1.Text
userpow = rs_login.Fields(2)
rs_login.Close
Unload Me
Form1.Show
Else
MsgBox "密码不正确", vbOKOnly + vbExclamation, ""
Text2.SetFocus
End If
End If
End If
cnt = cnt + 1
If cnt = 3 Then
Unload Me
End If
Exit Sub
End Sub

Private Sub Form_Load()
Dim connectionstring As String
connectionstring = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=F:\图书管理系统\db1.mdb;Persist Security Info=False"
conn.Open connectionstring
cnt = 0
End Sub