frmlogin.frm

这是别人的数据库课程设计

VERSION 5.00
Begin VB.Form frmLogin 
   BorderStyle     =   3  'Fixed Dialog
   Caption         =   "系统登录"
   ClientHeight    =   1965
   ClientLeft      =   45
   ClientTop       =   330
   ClientWidth     =   3840
   ControlBox      =   0   'False
   LinkTopic       =   "Form1"
   MaxButton       =   0   'False
   MinButton       =   0   'False
   ScaleHeight     =   1965
   ScaleWidth      =   3840
   ShowInTaskbar   =   0   'False
   StartUpPosition =   1  '所有者中心
   Begin VB.CommandButton cmdCancel 
      Caption         =   "取消"
      Height          =   375
      Left            =   1920
      TabIndex        =   5
      Top             =   1320
      Width           =   975
   End
   Begin VB.CommandButton cmdOK 
      Caption         =   "确认"
      Default         =   -1  'True
      Height          =   375
      Left            =   840
      TabIndex        =   4
      Top             =   1320
      Width           =   975
   End
   Begin VB.TextBox txtPassword 
      Height          =   270
      IMEMode         =   3  'DISABLE
      Left            =   1080
      PasswordChar    =   "*"
      TabIndex        =   3
      Text            =   "txtPassword"
      Top             =   840
      Width           =   2055
   End
   Begin VB.TextBox txtName 
      Height          =   270
      Left            =   1080
      TabIndex        =   2
      Text            =   "txtName"
      Top             =   480
      Width           =   2055
   End
   Begin VB.Label Label2 
      AutoSize        =   -1  'True
      Caption         =   "密码："
      Height          =   180
      Left            =   360
      TabIndex        =   1
      Top             =   840
      Width           =   540
   End
   Begin VB.Label Label1 
      AutoSize        =   -1  'True
      Caption         =   "用户名："
      Height          =   180
      Left            =   360
      TabIndex        =   0
      Top             =   480
      Width           =   720
   End
End
Attribute VB_Name = "frmLogin"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Private Sub cmdCancel_Click()
If MsgBox("您真的要退出本系统的使用吗？", vbYesNo + vbQuestion, "退出询问") = vbYes Then
   '把记录集从内存中清除
   Set adoRS = Nothing
   '断开与数据库的连接
   adoCon.Close
   '把连接变量从内存中清除
   Set adoCon = Nothing
   '从内存中卸载登录窗体，终止程序的执行
   Unload Me
End If
End Sub

Private Sub cmdOK_Click()
'运行时自动检测错误，检测到则到ErrMsg标号处做相应的处理
On Error GoTo ErrMsg
Dim SQL As String   '定义一个保存SQL语句的变量
'到Login 表中查询是否有符合条件的记录存在
'使用的是Select Count(*) From ...返回值是一个大于等于0的整数
SQL = ""
SQL = "Select Count(*) From Login Where Name='" & Trim(txtName.Text) & "'"
SQL = SQL & " And Password='" & Trim(txtPassword.Text) & "'"
Set adoRS = adoCon.Execute(SQL)
If adoRS(0) = 0 Then
   MsgBox "您输入的用户名或密码有误！", vbOKOnly + vbExclamation, "系统提示"
   txtName.SetFocus
   Exit Sub
End If
'卸载登录窗体
Unload Me
'显示系统界面，可以进入系统操作
frmSystem.Show

'错误处理
ErrMsg:
  If Err.Number <> 0 Then
     MsgBox CStr(Err.Number) + Err.Description, vbOKOnly + vbCritical, "错误提示"
     Exit Sub
  End If

End Sub

Private Sub Form_Load()
On Error GoTo ErrMsg

'清空文本框
txtName.Text = ""
txtPassword.Text = ""

'调用模块中的ConnectDB过程连接数据库，可以把连接模块直接写在这里
Call ConnectDB

'错误处理功能
ErrMsg:
  If Err.Number <> 0 Then
    MsgBox Err.Number & Err.Description, vbOKOnly + vbCritical, "出错提示"
    Exit Sub
  End If
End Sub