Question

我使用登录表单创建了一个简单的数据库。

我有一个带有AccessLevelID（autonumber）和Accless Level的tblAccessLevel，与用户表“tblUsers”有关系添加新用户后，您可以选择所需的访问级别。

我试图添加规则，以便在打开某些表单时，它会查看登录的用户，看看他们是否具有正确的访问级别，然后允许或拒绝它们。

这是我的代码：

UserView = DLookup("AccessLevel", "tblUsers", "[curUser] = " & [AccessLevel])
If UserView = "1" Then
Me.Command0.Enabled = True
Else: UserView = "3" Or "2"
Me.Command0.Enabled = False
End If

curUser在登录表单中定义：

curUser = DLookup("Username", "tblUsers", "[Username]=""" & Me.txtUsername.Value & """")

亲切的问候，阿什利

Main_Form

Private Sub Form_Load()
Set dbLog = CurrentDb
Set LogRec = dbLog.OpenRecordset("tblLog")
LogRec.AddNew
LogRec("eDate").Value = Date
LogRec("eTime") = Format(Now, "Long Time")
LogRec("Form").Value = "Main Form"
LogRec("User").Value = curUser
LogRec("Detail").Value = curUser & " Opened Main Form"
LogRec.Update

UserView = DLookup("AccessLevel", "tblUsers", "[curUser] = " & [AccessLevel])

If UserView = 1 Then
Me.Command0.Enabled = True
Else
Me.Command0.Enabled = False
End If

End Sub

Form_Login（带代码的登录命令）

Public Sub cmdLogin_Click()
Dim dbLog As DAO.Database
Dim LogRec As DAO.Recordset

'Check to see if data is entered into the Username Field
If IsNull(Me.txtUsername) Or Me.txtUsername = "" Then
    MsgBox "You must enter a Username.", vbOKOnly, "Required Data"
    Me.txtUsername.SetFocus
Exit Sub
End If


'Check to see if data is entered into the password box

If IsNull(Me.txtPassword) Or Me.txtPassword = "" Then
MsgBox "You must enter a Password.", vbOKOnly, "Required Data"
Me.txtPassword.SetFocus
Exit Sub
End If

'Check value of password in tblEmplyees to see if this matched value chosen in Username Field

If Me.txtPassword.Value = DLookup("Password", "tblUsers", "[Username]=""" & Me.txtUsername.Value & """") Then
curUser = DLookup("Username", "tblUsers", "[Username]=""" & Me.txtUsername.Value & """")

Set dbLog = CurrentDb
Set LogRec = dbLog.OpenRecordset("tblLog")
LogRec.AddNew
LogRec("eDate").Value = Date
LogRec("eTime") = Format(Now, "Long Time")
LogRec("Form").Value = "Login"
LogRec("User").Value = curUser
LogRec("Detail").Value = "User " & curUser & " Logged in"
LogRec.Update


MyEmpID = Me.txtUsername.Value

'Close Logon form and open splash screen

DoCmd.Close acForm, "frmLogin", acSaveNo
DoCmd.OpenForm "MainForm"

Else

Set dbLog = CurrentDb
Set LogRec = dbLog.OpenRecordset("tblLog")
LogRec.AddNew
LogRec("eDate").Value = Date
LogRec("eTime") = Format(Now, "Long Time")
LogRec("Form").Value = "Login"
LogRec("User").Value = "N/A"
LogRec("Detail").Value = "Someone tried to access your database with an invalid password"
LogRec.Update


MsgBox "Password invalid. Please try again", vbCritical + vbOKOnly, "Invalid Entry!"
Me.txtPassword.SetFocus

End If

'If User Enters incorrect password 3 times database will shutdown
intLogonAttempts = intLogonAttempts + 1
If inLogonAttempts > 3 Then
MsgBox "You do not have access to this database. Please contact your system administrator.", vbCritical, "Restricted Access!"
Application.Quit
End If
End Sub




Private Sub Form_Load()
Set dbLog = CurrentDb
Set LogRec = dbLog.OpenRecordset("tblLog")
LogRec.AddNew
LogRec("eDate").Value = Date
LogRec("eTime") = Format(Now, "Long Time")
LogRec("Form").Value = "Login"
LogRec("User").Value = "N/A"
LogRec("Detail").Value = "Someone logged into your database"
LogRec.Update
End Sub

ModCurUser

Option Compare Database
Public curUser As Variant

ModUserView

Option Compare Database
Public UserView As Variant

错误出现在：

UserView = DLookup("AccessLevel", "tblUsers", "[curUser] = " & [AccessLevel])

Answer 1

假设'curUser'是全局变量，可供所有VBA模块使用，您也可以将'UserView'设为GV。然后，是的，您可以根据“UserView”启用或禁用“切换板”命令按钮。如果您担心创意人员只需手动打开表单，那么您可以在表单中添加代码，如：

Private Sub Form_Load()
If UserView = 1 Then
    ' no action necessary - allow access
Else
    MsgBox "You do not have permission to use this form"
    DoCmd.Close acForm, Me.Name
End If
End Sub

您可能感兴趣的其他一些观察结果：

变量'intLogonAttempts'需要在Form级别定义 - 而不是在子程序内定义。如果没有，它将永远不会正确计算尝试次数（将始终为1）。
当您加载登录表单时，您说'N / A'正在尝试登录。最好跟踪用户登录名或工作站名称，即Environ $（“Username”）或Environ（“computername” “）

在比较验证密码时，某些应用程序可能希望强制进行100％的比较。目前，您的测试不会强制用户匹配密码的CASE。以下是一个简单的解决方案：

If Len(Me.txtPassword.value) = Len(<from your Dlookup>) Then
    For i = 1 To Len(<from your Dlookup>)
        If Asc(Mid$(Me.txtPassword.value, i, 1)) <> Asc(Mid$(<from your Dlookup>, i, 1)) Then
            blnWrongPWD = True
        End If
    Next i
Else
    blnWrongPWD = True
End If

祝你好运，Wayne

登录表单，具有访问权限

1 个答案: